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Author Topic: Pontiac 400-455 Questions and answers. Subthread  (Read 165746 times)

TA Addict

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #40 on: March 03, 2008, 02:54:42 PM »
79solargoldTA said:
Quote
Hey guys, I need some carburetor help on my 400. It's a 77' block with a Q-jet off of my old 403. My question is: My secondary's aren't opening up with acceleration and even on WOT. I was wondering if you guys had any ideas to why this might be happening?

  Can you open the primaries all the way and verify that the secondary throttle valves are opening all the way too?   You'll have to hold the secondary top butterfly valves open by hand and look down inside the carb to be able to see the actual secondary throttle valves.   Once the secondary throttle valves do open there is nothing mechanical involved in opening the secondary butterfly valves.   They operate purely be airflow.

  Did you make any adjustment to the tensioning screw that controls the force required to open the secondary butterfly's?   Probably not as they aren't something that jumps out at you unless you're really looking for them.

  Guess I should really ask 1st how you know the secondaries aren't opening.   Is it just that you never feel a sudden surge of power?   Some cars are adjusted well enough that you don't feel a sudden kick when the secondaries open.   

  Check the two above suggestions and if see if that helps - if not come back and I'll do what I can to help.

  TA Addict
1979 Trans Am, 400 Pontiac, T350
1977 Trans Am, 454 Chevy, T400
1973 Grand Am, 455 Pontiac, T 400
1964 Chevy 4x4 Truck, 350 Chevy

brian c

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #41 on: March 06, 2008, 08:20:01 AM »
Need some engine building suggestions for a 400 I'm going to be building for my sister. She wants a good smooth idle and no where near the 400hp my built 469 is pushing.

I was thinking of an Edelbrock Performer intake/cam/lifter setup but I'd like it to be a tad warmer than the stock 200/220hp these pushed out. I'm thinking somewhere in the neighborhood of 250-275hp at the crank. Any thoughts on a good cam to run with the Performer intake?

Head wise I'll probably snag a set of 6x-8's off ebay and have them gone through. Gear wise I'm thinking of 3.08:1's so she gets decent gas mileage and I'll add in a posi while I'm at it. Tranny wise I'm looking at a TH350.
1978 Y88 Gold Special Ed (1970 4 bolt main 455 bored 0.060 over)

BoDarvelle

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #42 on: March 09, 2008, 01:27:42 PM »
I just finished the swap from a 400 to a 455 in my T/A. 

I could help if anyone has any questions :cool:










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chief poncho

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #43 on: March 21, 2008, 04:24:32 PM »
WOW! Very nice and what looks to be a very potent poncho powerplant in that bird.
1971 Lucerne Blue Trans Am (455HO, Automatic) - currently my project car.
Previously Owned TA's/Musclecars: 2002 Pewter WS6/M6 Trans Am, 1968 Dodge Superbee 383/4speed,  1975 TA 455/4speed, 1989 Mustang LX 5.0/5speed, 1980 TA Indy Pace Car, 1977 TA 400/Auto, 1989 GTA 350TPI, 1990 GTA 350TPI, 1986 IROC 305TPI, 1989 Mustang LX 5.0/Auto, 1993 Mitsu 3000GT VR4 (and probably a few I've forgotten about)

TnVTX

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #44 on: March 21, 2008, 04:35:28 PM »
Bo,
Where did you get that shaker lower pan/air cleaner assembly?
I have a WFO, and my shaker still sits too high.
I'm also thinking about switching to a "Dude" scoop also.


'78 W-72 T/A w/468" Forged Stroker Kit, E-Heads, etc.
'07 Solstice GXP (Turbo)
'81 4-spd Vette
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Doug

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #45 on: April 15, 2008, 07:34:14 PM »
Bo,
Where did you get that shaker lower pan/air cleaner assembly?
I have a WFO, and my shaker still sits too high.

I did have that same problem but Larry Navarro figured it out from the pics.  The shaker had been moved about an inch forward on the base.  Once I put it back it worked perfectly.
« Last Edit: April 18, 2008, 05:54:04 PM by Doug »

Donkey

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #46 on: April 22, 2008, 01:45:12 PM »
Im pretty sure the 350 driveshaft will work...not 100% sure though...
1951 Ford F2 226/3spd
1971 Camaro 355/4spd - Sold :(
1978 Trans Am SE 400/4spd
1979 Trans Am Tenth Anniversary 400/4spd - In pieces
1981 Chevrolet C10 350/4spd - Blah
1987 Buick Grand National - Tons of Go-Fast goodies :)

grenggli

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #47 on: April 22, 2008, 08:29:09 PM »
Concerning 455 with th400 COMBO in 1980.  I did this in a 1981 and you do have to have a shorter driveline because the TH400 is longer by @1 inch.  You can have a driveline shop cut down your TH350 one but you will need to attach a TH400 yoke because they have a larger output shaft.  I got lucky and purchased a shorter one out of a car with your set up for mine and it fit perfectly.  If you try to use the TH 350 driveline without shortening it, you are likely going to have issues since the slip yoke is not going to be inside the transmission at a spot where the rearend going up and down can have room to move and slip with it.  Good luck on your modifications.
1981 Blk & Gold Pontiac TTA with  455 SE clone--selling
1978 Silver Pontiac TA with BB 454 (sold)
1989 Maui blue Pontiac Firebird Formula--sold
1988 Flame Red Pontiac GTA 5.0TPI 5spd T-tops--sold

Tony79WS6

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #48 on: April 29, 2008, 02:34:20 PM »
Hey, I have a few questions for you guys. I am building up a Pontiac 400 right now, and I have a question about windage trays and crank scrapers. First off, the motor is a 1974 block, and when I took it apart, there was no windage tray in there. It's being built for street/strip duty with a stock-style oil pan. Do I need to get a windage tray, a crank scraper, both, or neither? I don't want to have oil starvation issues on my new motor.

Also, I'm running 1971 #96 D-port heads and was wondering if I have to drill extra bolt holes to mount a set of headers. I am probably going with some Hedman 28156's, and on Summit's website, it says that some heads need to be drilled for extra mounting holes.

Thanks!!! 8-)
« Last Edit: April 29, 2008, 02:37:59 PM by Tony79WS6 »
-1979 WS6 T/A

Rick

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #49 on: April 29, 2008, 07:06:48 PM »
Pontiac stopped using windage trays in the early 70s.  They were not in the 74-76 engines I've had.  If you're concerned about oil starvation you should look into an accusump.  That provides about a quart of oil reserve at system pressure in case the pickup gets uncovered.  Mine has worked pretty well. ;)

Tony79WS6

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #50 on: May 06, 2008, 11:03:06 AM »
I have some more questions about my 400 build for you guys.  :smile:

1. On the subject of the windage tray again, do I really need one? I spoke with my engine builder today, and he said that it was definitely a good idea to get a stock-style one, but I'm also going to have to get different main cap bolts for my 1974 block, because it was not originally equipped with one. I am having trouble finding both the tray and the bolts together. Does it really matter that much?

2. I need to know what I need inside of the timing cover when it comes to cooling stuff. Right now, I just have the cover, and I know I need a water pump divider plate, but what else do I need? 

3. I plan on running an Edelbrock Performer RPM manifold on my 1971 #96 heads, and I want to know if I need to block off the heat crossovers on the heads. Does that manifold already do that, or is there something else I need to buy?

4. And one more quick thing: I need a heater hose nipple for my cylinder head, because mine is not useable anymore. Ames Performance has them backordered, and I want to know if there is somewhere else I could get them.

Thanks!!!
-1979 WS6 T/A

brian c

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #51 on: May 06, 2008, 11:43:27 AM »
1. You can buy an aftermarket tray and bolts - I want to say Milidon (sp?) but I don't have a catalog handy. When I bought my stock windage tray it did not come with the mounting bolts and I believe the machine shop just supplied those when they assembled the engine for me.

2. If you have the divider plate you're almost there. There's (2) inserts that you may/may not have already in the timing chain cover. If you don't have them you need to get them. They look like this:



3. I didn't have anything filled in my heads and its run for 500 miles so far. Nothing was mentioned by either the machine shop or by Muscle Car Alley when I had them fix the intake gasket issue the machine shop created.

4. I've heard that you can get them right from your GM dealer. Otherwise I'd wager you can find them at any pontiac parts dealer - Franks Pontiac Parts lists them on their website for ~$30 (http://www.frankspontiacparts.com/usedparts/pontiacengineparts.htm) OR Spotts has them listed for $22 (http://www.spottsperformance.com/cooling%20system).
1978 Y88 Gold Special Ed (1970 4 bolt main 455 bored 0.060 over)

Tony79WS6

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #52 on: May 07, 2008, 01:07:34 PM »
Are these the same as the steel ones? BOP Engineering sells these rubber ones, and I just wanted to make sure they work before I buy them. They are the only ones who have both the heater outlet for the head and the water pump plate in stock, so if I could get it all in one shot, that would be awesome.

Also, I was flipping through my How To Build Max Performance Pontiac V8s book last night, and it says that windage trays are pretty much unnecessary at the power level I'd be running, so I think I'll go without one.

I have another question about shaker height and intakes. If I use a Holley 4150-series with a stock or Edelbrock Performer intake with a 1 inch spacer/adapter, would that screw up shaker height? I would think that it would, but I'm just checking.
-1979 WS6 T/A

mark369

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #53 on: May 07, 2008, 01:19:56 PM »
 On my 78 400 Pontiac head there is a port in the center on top to the intake manifold that is not covered by the gasket and with the intake on it is part visible and open to collect water cause my Mr gasket scoop does not allow a seal to the hood. Is there a purpose to this? 


72blackbird

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #54 on: May 14, 2008, 12:32:21 AM »
The center port is there to allow exhaust gas to enter a chamber under the stock manifold and warm the incoming A/F mix going into the intake ports (supposed to help atomize the fuel better). You will need to get intake gaskets that line up to these center ports if you are running the stock manifold, or a gasket that covers the hole completely if you using an aftermarket manifold. Fel-Pro covers just about every production Pontiac gasket you would need- ask your local speed shop or auto store to check their catalog for the right part no.

Geno
1977 SE T/A (sold :( )
1974 455 T/A (sold :( )
1972 Esprit restomod
1976 T/A restomod
1975 Formula 400 4-speed donor car
1978 Martinique blue W72 4-speed T/A, hurst tops

Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #54 on: May 14, 2008, 12:32:21 AM »


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mark369

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #55 on: May 14, 2008, 01:47:00 PM »
That is the gasket that was on the car and the replacement one from Advance auto parts matches it!   Any idea what gasket # I should use & where to get it.  As is water gets in there and then boils out when I run the car.  Not good in winter. Its a wonder I have not had issues in the past. Ben that way for 10 years.

72blackbird

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #56 on: May 14, 2008, 08:26:27 PM »
That gasket is for a 68-71 head (my no.48s have the smaller exhaust port hole)- Fel-Pro makes the correct gasket for your application, where the top edge of the gasket runs straight across and seals that hole. BTW, what is the head no., 6X ? Are you running the stock manifold, or aftermarket? You may have to contact an expert Pontiac builder to get the right gasket.

Geno
1977 SE T/A (sold :( )
1974 455 T/A (sold :( )
1972 Esprit restomod
1976 T/A restomod
1975 Formula 400 4-speed donor car
1978 Martinique blue W72 4-speed T/A, hurst tops

CopMagnet

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #57 on: May 15, 2008, 08:01:34 AM »
I'm looking for a poncho engine to replace a 403.  I'm torn between a 400 and a 455.  Are there any good links anyone can provide to inform me of the TRUE differences.  I've always heard vague info about the subject.  Like, They're the same engine, the 455 just has a larger bore....etc.  Forgive me, I know my way around a car, but I'm not an engine expert.  Thank for any info

No Brake!  All Pedal!!

72blackbird

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #58 on: May 15, 2008, 02:10:42 PM »
CopMagnet,
The 400 has a 3.00 main journal dia., 4.120 bore x 3.75 stroke, and the 455 has a 3.25 journal dia., 4.15 bore x 4.21 stroke. The 455 has more torque, but the 400 is known for its ability to rev- both use the 6.625 rod.

I personally would get a Poncho 400, and then get either a 455 or 462 stroker kit. A stroked 455/462 Pontiac is better than a stock 455, because of the smaller main journal diameter (3.00 vs. 3.25) and its ability to rev faster (also related to main journal diam.). The 455 stroker kit uses a 6.625 (stock Pontiac length) rod and 4.21 stroke crank, while the 462 uses a BBC 6.8 rod and 4.25 stroke- the jury is out on which stroker is best, but in either case you can upgrade from a cast crank to a forged unit for $300 more. Both kits offer either 4340 I-beam or H-beam rods. The 462 also uses custom pistons, but those are usually lightwieght race units w/ floating pins. Butler Racing, Ohio Crankshaft, SD Performance, and Pacific Performance racing all offer stroker kits fof around $1400-2100.

Geno


1977 SE T/A (sold :( )
1974 455 T/A (sold :( )
1972 Esprit restomod
1976 T/A restomod
1975 Formula 400 4-speed donor car
1978 Martinique blue W72 4-speed T/A, hurst tops

CopMagnet

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #59 on: May 15, 2008, 06:41:03 PM »
That's some good info Geno, and hey, welcome to TAC bro!  Thanx   :cool:

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72blackbird

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #60 on: May 16, 2008, 12:28:01 AM »
CopMagnet,
No worries-glad I could share. BTW, when you're block shopping avoid any 400 blocks numbered #500557 and #568557- these are the thin-wall castings that came out in mid '75 to save weight. I have seen these at Pacific Performance racing in Ace's shop, and there is a big difference in wall thickness. I suppose they're okay for a stock  build-up, but not for a 550-hp 455 or 600-hp 462. Jim Hand's book aslo mentions the #481988 blocks, but I've got two and both of them are thick under the main caps (works for me).

Geno
1977 SE T/A (sold :( )
1974 455 T/A (sold :( )
1972 Esprit restomod
1976 T/A restomod
1975 Formula 400 4-speed donor car
1978 Martinique blue W72 4-speed T/A, hurst tops

CopMagnet

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #61 on: May 17, 2008, 12:33:13 AM »
Geno, I am now officially required to buy you a beer.  I have an old knucklehead buddy from way back in high school, he swears 455 is better.  Well, I have thrown some info at him but, to no avail.  he went to mechanic school after leaving the army and I think he's pretty good.  However............some things just don't always add up.  He blew up 3 400's, well, maybe those were the ones with the thin wall castings that he didn't know about.  Can't wait to throw that at him to see what he says.  Hopefully, he'll man up and admit he didn't know about it.  I'm gonna look for a 400 just to piss him off.  I keep telling him to get on the net and join the 21st century, but he's one of those guys...    Geno, you rock, thanx  Chris Rocklin

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72blackbird

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #62 on: May 18, 2008, 12:44:38 PM »
Chris,
I've blown up a couple of 400's myself- the frist one threw a rod and grenaded that block, the second broke a crank but the block survived (!). You have to rev them for a bit for this to happen, but I'll tell you firsthand that stock Pontiac cast rods and cranks weren't meant for top end or road racing. Good thing there are plenty of sources for forged Pontiac rods and cranks now- we can build up a strong motor just the Chevy and Ford guys and show them how a Poncho makes power.

BTW, you don't need 4-bolt main caps- if you find a 2-bolt block, just run ARP  main studs- the general consensus is that they're good to 600-650 hp. And the cast cranks are strong enough if you keep the revs down and prep it properly (I personally would still get a forged crank 'cause it's only $350 more, and for the peace of mind). I'll buy the second round if you're ever in SoCal...

Cheers,
Geno
1977 SE T/A (sold :( )
1974 455 T/A (sold :( )
1972 Esprit restomod
1976 T/A restomod
1975 Formula 400 4-speed donor car
1978 Martinique blue W72 4-speed T/A, hurst tops

Rob

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #63 on: May 18, 2008, 08:31:36 PM »
can somebody help me ID my 455? comparing my code to 78ta.com's engine ID's, im guessing it's a 1970 455 HO? It's a Pontiac block for sure though right? My reading was engine code:YC casting code:C293897; Im also trying to ID my 400..sorry for it being blurry, my battery was dying out so I had to take it fast..ill take a clearer picture tomorrow..this is what i got for the 400; engine code:YH casting code:0151580 Im guessing its a 1974 400?.. Can anybody help me ID what I got? thnx in advance


455 Block



400 Block
« Last Edit: May 18, 2008, 08:43:25 PM by BigRob4rmTX »

Rick

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #64 on: May 18, 2008, 08:50:24 PM »
You have the entire list of possible combinations, don't you?  This site lists them all and has been pretty accurate from all reports.

http://www.teufert.net/identify/identify.htm

Jdogg

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #65 on: May 21, 2008, 06:53:02 AM »
i just bought a Turbo Trans Am that has a olds 455 in it, it dont work the guy that i bought from said he thinks it has a spun bearing maybe, is the motor worth saving? does it have any value to it? I think i am going to put a 355 int he car any special things i should know? It has a BW trans

thanks
94 Trans Am GT, LT1, hard top and 1 of about 457 yellow birds made!!!

BAN

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #66 on: June 05, 2008, 11:29:31 AM »
Roller Cam in a 400?

Looking at rebuilding my top end, aluminum heads, carb and intake. Along with a r-cam. Is anyone running roller lifters in their 400 without a lifter guide plate? Is it something you can do as long as your cam is less than xxxx?

I'm asking as i dont want to have to tap threads into the valley to install the plate, and someone i was talking to on the weekend said something along the lines of "i'd never go a roller without a lifter guide in those engines" But im not too sure on this guys knowledge, seems to be one of those guys who talks alot.

Cheers
Sam.


77 Pro Street, 454 BBC, 8-71 Dyers, back halfed.
77 455, E headed, roller, 10.5:1 475hp/575lbs
71 T-37, 350.

Enzo_Guy

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #67 on: June 22, 2008, 08:08:51 PM »
And the cast cranks are strong enough if you keep the revs down and prep it properly (I personally would still get a forged crank 'cause it's only $350 more, and for the peace of mind).

John Kaase actually used a cast steel crank in his first Pontiac Engine Masters entry and it held up just fine he said.

Enzo_Guy

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #68 on: June 22, 2008, 10:02:58 PM »
can somebody help me ID my 455? comparing my code to 78ta.com's engine ID's, im guessing it's a 1970 455 HO? It's a Pontiac block for sure though right? My reading was engine code:YC casting code:C293897; Im also trying to ID my 400..sorry for it being blurry, my battery was dying out so I had to take it fast..ill take a clearer picture tomorrow..this is what i got for the 400; engine code:YH casting code:0151580 Im guessing its a 1974 400?.. Can anybody help me ID what I got? thnx in advance

This is a list of what a YC block could be:
YC A-body 76 400 170 Turbo 350 L-65 N 1x2 500557 2 AC
YC B-body 76 400 170 Turbo 350 L-65 N 1x2 500557 2 AC
YC B-body 76 400 170 Turbo 350 L-65 N 1x2 500557 2 AC
YC B-body 65 389 290 Turbo 400     1x2 9778789 2 AC
YC B-body 66 389 290 Turbo 400     1x2 9778789 2 AC
YC B-body 67 400 290 Turbo 400     1x2 9786133 2 AC
YC A-body 72 455 250 Turbo 400 L-75 Y 1x4 485428 2 GTO
YC A-body 71 455 325 Turbo 400 L-75   1x4 485428 2 GTO
YC A-body 70 455 360 Turbo 400 L-75   1x4 9799140 4 GTO Judge HO
YC B-body 69 400 290 Turbo 400     1x2 9790071 2 int seat 30
YC A-body 74 350 170 Turbo 350 L-30 N 1x2 488986 2 low comp
YC F-body 74 350 170 Turbo 350 L-30 N 1x2 488986 2 low comp
YC A-body 73 455 250 Turbo 400 L-75 Y 1x4 485428 2   
YC B-body 72 455 250 Turbo 400 L-75 Y 1x4 485428 2   
YC B-body 72 455 250 Turbo 400 L-75 Y 1x4 485428 2   
YC B-body 73 455 250 Turbo 400 L-75 Y 1x4 485428 2   
YC B-body 73 455 250 Turbo 400 L-75 Y 1x4 485428 2   
YC B-body 71 455 325 Turbo 400 L-75   1x4 485428 2   
YC B-body 71 455 325 Turbo 400 L-75   1x4 485428 2   
YC B-body 68 400 290 Turbo 400     1x2 9790071 2   
YC F-body 73 455 250 Turbo 400 L-75 Y 1x4 485428 2   
YC F-body 71 455 325 Turbo 400 L-75   1x4 485428 2   

Your casting code is not the number just above the block code, your casting code is actually on the block under the distributor cap.

ole farmer

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #69 on: June 24, 2008, 10:01:30 AM »
On my 78 400 Pontiac head there is a port in the center on top to the intake manifold that is not covered by the gasket and with the intake on it is part visible and open to collect water cause my Mr gasket scoop does not allow a seal to the hood. Is there a purpose to this? 


I just noticed this on my 76 400 also. the Gasket covered (and sealed) the exhaust port but there is a small void above the exhaust port that is sort of no-mans land ??? The intake manifold has the smaller exhaust transfer port and all the intake ports line up but not the heat riser port. Did my engine get a manifold swap or is this just the way it is???? Thanks Guys...Garry

bandit79

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #70 on: July 03, 2008, 08:14:01 AM »
Roller Cam in a 400?

Looking at rebuilding my top end, aluminum heads, carb and intake. Along with a r-cam. Is anyone running roller lifters in their 400 without a lifter guide plate? Is it something you can do as long as your cam is less than xxxx?

I'm asking as i dont want to have to tap threads into the valley to install the plate, and someone i was talking to on the weekend said something along the lines of "i'd never go a roller without a lifter guide in those engines" But im not too sure on this guys knowledge, seems to be one of those guys who talks alot.

Cheers
Sam.




Sam,

While regular tappet lifter actually rotate in the lifter bore, roller lifters have to stay in one position. Therefore, you will need something that keeps them from rotating. A lot of the aftermarket roller lifters are tied together in pairs by a tie bar to keep them from rotating, they look like this  http://www.compperformancegroupstores.com/store/graphics/00000001/High_Energy_Hydraulic_Lifters_853_600x600.jpg, or they have retainers that slide over a pair and then the "spider" plate is bolted to the center of the valley that has "arms" that hold the retainers and it looks like this, http://www.compperformancegroupstores.com/store/graphics/00000001/Hydraulic_Roller_Lifter_Installation_Kit_08-1000_600x600.jpg

You will need either one or the other. But you have to run one of these setups. So yes you can run without the big plate in the valley, but you will have to run them with the tie bars. I hope this helps you figure it out.
David
1979 Trans Am

BAN

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #71 on: July 11, 2008, 12:15:00 AM »
Thanks for the reply! Yeah im aware of the link bars used when retrofitting roller lifters to an engine (been around chevys quite sometime) This all started when some guy up here who supposedly "knows pontiacs" mentioned i wouldnt be able to get any lift due to the lack of length in the lifter bores themselfs. He basically explained to me that the lifters would "walk" around without a guide plate when they were at their highest lift. It confused me as ive never heard of this, even in custom race blocks where cams have been relocated.

Anyhow after digging into this 400 and reading a few things i realized he was totally full of B/S, and he owns a "performance store"  :shock:

So thanks for the reply, and while we are here. I thought i read something about replacing the stock valley pan due to clearance issues from the link bars in the roller cam, is this the case? or are you guys running stock pans with a roller setup?

77 Pro Street, 454 BBC, 8-71 Dyers, back halfed.
77 455, E headed, roller, 10.5:1 475hp/575lbs
71 T-37, 350.

Rebel 5150

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #72 on: July 11, 2008, 10:53:12 AM »
On my 78 400 Pontiac head there is a port in the center on top to the intake manifold that is not covered by the gasket and with the intake on it is part visible and open to collect water cause my Mr gasket scoop does not allow a seal to the hood. Is there a purpose to this? 


I just noticed this on my 76 400 also. the Gasket covered (and sealed) the exhaust port but there is a small void above the exhaust port that is sort of no-mans land ??? The intake manifold has the smaller exhaust transfer port and all the intake ports line up but not the heat riser port. Did my engine get a manifold swap or is this just the way it is???? Thanks Guys...Garry

Are you talking about the 'port' that is cicrled in red in this picture?


If so, the gasket is not supposed to cover that.
Harold- Pure Trans Am Nut


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mark369

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #73 on: July 11, 2008, 11:16:44 AM »
Yes the port circled in RED!  Ok, it is not supposed to be covered. But why? is it left open.  With a properly sealed shaker it does not get rain in it. With my Mr. Gasket scoop set up it fills with rain water and boils out when running. Worried about winter water freezing in it.   

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #74 on: July 11, 2008, 12:56:00 PM »
Yes the port circled in RED!  Ok, it is not supposed to be covered. But why? is it left open.  With a properly sealed shaker it does not get rain in it. With my Mr. Gasket scoop set up it fills with rain water and boils out when running. Worried about winter water freezing in it.   

  Pontiac added it to keep the hot exhaust gases away from the oil soaked areas under the rocker cover and baking it in there.
Harold- Pure Trans Am Nut


After all these years of bright lights, I still don't need glasses--I drink straight from the bottle.-David Lee Roth

Tony79WS6

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #75 on: July 11, 2008, 02:22:47 PM »
Here's a question that I hope someone can answer:

I'm putting my 400 on an engine stand tonight for assembly (I just got it all back from the machine shop!!!!!  :D) and I need to know what size the bolts are on the transmission side of the motor so I can mount it up on the stand. Please let me know if anyone knows! Thanks!  :cool:
-1979 WS6 T/A

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #76 on: July 11, 2008, 02:27:53 PM »
3/8" coarse (16 threads per inch).
Harold- Pure Trans Am Nut


After all these years of bright lights, I still don't need glasses--I drink straight from the bottle.-David Lee Roth

Tony79WS6

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #77 on: July 11, 2008, 02:43:04 PM »
Thank you very much!!! I can't wait to get this beast in the car.
-1979 WS6 T/A

Tony79WS6

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #78 on: July 22, 2008, 03:11:43 PM »
Here's another question for you guys: What's the best way to put headers in the car with the engine already out? Should I atach the collectors to the rest of the exhaust and drop the motor on top of them, or should I attach the headers to the motor while it's still on the stand and drop it all in at once?

Thanks!
-1979 WS6 T/A

Doug

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Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #79 on: July 25, 2008, 10:02:48 AM »
Here's another question for you guys: What's the best way to put headers in the car with the engine already out? Should I atach the collectors to the rest of the exhaust and drop the motor on top of them, or should I attach the headers to the motor while it's still on the stand and drop it all in at once?

Thanks!

Generally you are better off setting the headers down then lowering the motor until it is a few inches above the mounts then attach the headers.  Of course if you are using shortys then attach them first and drop the whole thing in.

Re: Pontiac 400-455 Questions and answers. Subthread
« Reply #79 on: July 25, 2008, 10:02:48 AM »
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