Author Topic: LS1 or LS3? looking for advice, 1979 Trans AM  (Read 647 times)

boeing9999

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LS1 or LS3? looking for advice, 1979 Trans AM
« on: November 09, 2017, 11:36:27 AM »
Hello! I have a 1979 Trans AM
Those who have swapped LS1 or LS3, could you pls leave your comments -
1) Are you happy with the ammount of power your engine produces (currently, stock mode, or minimum add-ons)
2) Do you think LS1 power is good enough for daily street use, or after you get used to it, do you begin to wish for more?
3) How costly is it converting L92 into LS3?

I'm soon starting a LS swap. It will be a street car, no drag racing planned. Just aggressive street driving style sometimes)
Have two options at hand - one is a LS1/T56 kit from a 2001 Trans AM one guy wrecked (hit in the back). Has a LS6 intake. Everything else is stock in this kit. The set is available already and can be swapped the cheapest and the quickest.
Second is a cheap L92 engine from a 2007 Escalade to be changed into LS3 and swapped with some trans. I see T56 as the easiest way. 4l60e is harder (if I understand correctly?), because would require additional parts and work to mate it with a LS3. Also the offered L92 engine is more bare, than the LS1 from a wrecked car, only has an oil pump on it, so would have to buy additional stuff to make the swap complete.

So, are the LS3's more modern make and higher HPs worth the hustle and money for a street car swap vs LS1? My idea was, that in the future, if I have the bucks, I could install a supercharger from ZL1 or LSA and further increase the car's performance.

In terms of budget, 1st stage of upgrading for both LS1 and LS3 would cost around the same, right? - headers, cam, heads. But I could skip on that for some time with the LS3 (made from L92), because I already get 409HP vs the 325 of LS1. And LS3 upgrades would bring more HPs because of bigger displacement and newer architecture, correct?
Or maybe all this extra power isn't used in the street driving? Would very much appreciate if you share your thoughts, thank you in advance!

jonathonar89

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Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #1 on: November 09, 2017, 11:54:27 AM »
LS1 makes plenty power stock. I drive my ‘98 Trans Am everyday. 

Personally I would just build up whatever you already have in the car.  Most old engines can make 500-600hp with a set of aluminum heads...and they can be converted to port fuel injection. Fuel mileage most comes from gearing...overdrive transmission is where your fuel mileage picks up and they’re easy to install.
1979 Trans Am 400 T-top - Platinum Silver, Carmine Interior
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scarebird

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Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #2 on: November 09, 2017, 12:08:59 PM »
I installed a LS3 in my 79, coupled with a TKO-600.  If you have a LS1 with T56  and are not afraid to cut the tunnel if needed I would go that route.

Most of the changes between the generations are pretty minor, some are not: ie. drive by wire.

Bobby G

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Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #3 on: December 04, 2017, 08:53:53 PM »
I have a new LS3 in my 80 Trans am with a 4L80 E, 3600 converter, headers and a CAI. It made 385 RWHP and 367 RWTQ.....stock motor.....I was going to put a LS1 in my other 73 until I saw those numbers.....bought another LS3....its a beast....just saying

Bobby G

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Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #4 on: December 04, 2017, 08:55:44 PM »
BTW, I took it to work 3 times 60 miles one way and it only used a quarter tank of gas.

Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #4 on: December 04, 2017, 08:55:44 PM »

FormTA

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Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #5 on: December 04, 2017, 10:39:06 PM »
The more complete the better. I too thought the LS in stock form had plenty of power when I was driving my donor car around. The F Body LS one basically dropped right in like is was supposed to be there. If you swap your steering box out for a later quick ratio one with the metric fittings then the f body line bolt in too. The radiator, hoses and fans fit right in too. It is a really easy swap. My project runs but it's not on the road as I'm onto the bodywork now..
79 Trans am 301 (work in progress) LS swap n progress
79 Formula 301 (Work in progress)
67 RS Camaro (Work in progress)
See the recurring theme???

skisix38off

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Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #6 on: December 06, 2017, 07:28:00 AM »
I installed a LS3 in my 79, coupled with a TKO-600.  If you have a LS1 with T56  and are not afraid to cut the tunnel if needed I would go that route.

Most of the changes between the generations are pretty minor, some are not: ie. drive by wire.


I'm currently swapping a T56 in my '78 TA, I will be mating it to my Pontiac 400 but, I will not need to cut the tunnel to get it to fit where I want it.  I am far enough along that I am ready to start fabricating the crossmember and I am mounting it as high as I can to provide ground clearance.  I posted some pics in the Projects forum here about the T56.

scarebird

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Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #7 on: December 06, 2017, 05:08:25 PM »
I installed a LS3 in my 79, coupled with a TKO-600.  If you have a LS1 with T56  and are not afraid to cut the tunnel if needed I would go that route.

Most of the changes between the generations are pretty minor, some are not: ie. drive by wire.


I'm currently swapping a T56 in my '78 TA, I will be mating it to my Pontiac 400 but, I will not need to cut the tunnel to get it to fit where I want it.  I am far enough along that I am ready to start fabricating the crossmember and I am mounting it as high as I can to provide ground clearance.  I posted some pics in the Projects forum here about the T56.

Make sure the driveline angle is the same as the motor you pulled...

Old Chicken

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Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #8 on: December 06, 2017, 07:27:38 PM »
I wanted the LS3 but got a good deal on LS1/4l60e combo so going that route.  Planning on a Maggie down the road, should be good enough when done.  I'm using a C5 Corvette front drive and putting the AC on top left, there are companies that sell the brackets to do that.  IDK if the LSA would fit, might need a cowl, haven't seen that done with a shaker hood.  Guess it all comes down to what you want, I like the durability and lower cost of the LS1 but can't go wrong either way.   

1981RoadRace

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Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #9 on: December 12, 2017, 07:53:09 AM »
I've had 4 engines 8n my car, LS1 LS2 truck 5.3 and currently LS3.  The first was a service replacement pull long block that was removed by dealer for excessive valve train noise. I picked it up for $800 and ran it for 3 years at the track before it finally disintegrated a rod bearing. I still managed to sell the remains for more than eight hundred bucks. The LS2 probably would be in the to this day if I had not made a VERY expensive mistake with an aftermarket timing cover. The 5.3 was a stopgap JY motor used to complete the 2015 autocross season and was sold off when I lucked into the LS3.

All engines had great power and except for the LS2, were internally stock. Coupled to the T56, they all got great mileage--I average 23 mpg highway with the LS3. Btw, the LS1 was carburetor fed, not EFI.

As others have mentioned, the transmission tunnel had to be modified to fit the t-56. I also Used Corvette oil pans for all engines. The first three used the C5 batwing. The last one uses a C6.
Karl R. - Editor, Silver Blade Magazine
2008 Grand Prix GXP | 1981 Trans Am WS6 - LS3, T56 + other bits of gearhead joy.


ryeguy2006a

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Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #10 on: December 12, 2017, 01:47:43 PM »
If you are asking this question purely based on what engine is better for the long run, I would suggest the L92 motor. The only real difference is that the cam and intake. One cool thing I like about the L92 is that it has VVT and that makes for a broader torque curve, and they make aftermarket cams that take advantage of that. But that is another discussion.

Now, here is my other thought. If you are looking for the easiest and most cost effective of the two, far and away the LS1/t56. I have said it before, that aside from notching the frame for the low mount alternator (and A/C compressor if applicable) these motors basically fit right into the 2nd gen's. When I swapped my '99 LS1/t56 I didn't have to modify the tunnel at all aside from cutting a new hole for the shifter. The LS1 harness from Fbodies are very easily converted to stand alone, oil pan fits perfectly, and now there are several options for headers/mounts/efi ready fuel tanks. Also, if you want to save a little coin, see if they would sell you the fuel pump assembly and use a Vetteworks adapter to graft it to your stock tank.

Another thought is that once you have the motor in place and running/driving you can always swap out the ls1 for an ls3/l92. Only thing you would NEED to change would be the engine harness.

Just my two cents...

1976 Trans Am LS1, 6 speed, C5 12.8" Brakes, LS1 rear 12" brakes, 17" Aluminum Rims, and much more...SOLD
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New project: 1968 Camaro with 6?.?0?  5.3 w/ Z06 cam/T56
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Tony2424

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Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #11 on: December 22, 2017, 01:31:46 PM »
I'm doing a 6.0 swap and I have to say the brp hotrod mounts work great. I used there engine mounts and trans cross member and efi fuel tank..

boeing9999

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Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #12 on: December 29, 2017, 11:38:57 AM »
Thanks for advice everyone!
My LS swap started. It's LS1 and T56 from 2001 Trans AM.
I thought I'd go for long tube headers, but my mechanic persuades me they'll be bad for street use and ground clearance. He recommends mid-length headers.

What's your experience with headers, guys?


scarebird

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Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #13 on: December 29, 2017, 02:57:51 PM »
What's your experience with headers, guys?

Leave them at Summit and run manifolds - newer ones flow fine.

FormTA

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Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #14 on: December 29, 2017, 03:57:09 PM »
So where is the swap thread?  :D
79 Trans am 301 (work in progress) LS swap n progress
79 Formula 301 (Work in progress)
67 RS Camaro (Work in progress)
See the recurring theme???

Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #14 on: December 29, 2017, 03:57:09 PM »

Box

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Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #15 on: December 29, 2017, 04:25:11 PM »
Thanks for advice everyone!
My LS swap started. It's LS1 and T56 from 2001 Trans AM.
I thought I'd go for long tube headers, but my mechanic persuades me they'll be bad for street use and ground clearance. He recommends mid-length headers.

What's your experience with headers, guys?
<a href="http://www.youtube.com/watch?v=Y7_lSU3D0jw" target="_blank">http://www.youtube.com/watch?v=Y7_lSU3D0jw</a>
<a href="http://www.youtube.com/watch?v=rTlHEOE2Zp4" target="_blank">http://www.youtube.com/watch?v=rTlHEOE2Zp4</a>
« Last Edit: December 29, 2017, 04:28:03 PM by Box »

1996 Pontiac Firebird Formula hardtop 6-speed

Hutchman

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Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #16 on: December 29, 2017, 05:45:07 PM »
I have a new LS3 in my 80 Trans am with a 4L80 E, 3600 converter, headers and a CAI. It made 385 RWHP and 367 RWTQ.....stock motor.....I was going to put a LS1 in my other 73 until I saw those numbers.....bought another LS3....its a beast....just saying

This good info.....

I have an LS1 with a Blackwing lid, 1 7/8" headers into a 3" merge and an SLP Dual Dual muffler.  Since it's an 01 it has an LS6 intake with stock 241 heads.....but it has a rather large cam for the street.  It's a 238/242 .605/.610, 115 +3 Comp Cam.  The wide LSA calms the idle down enough to make it OK on the street, but it is kind of rowdy!  I have a dyno sheet showing 407 hp at the rear wheels.

My point being.....a milder cam would put the car in the 385 hp range.  An LS1 will take all the bolt ons plus a cam to make the same power as a bolt on LS3.  The LS3 is slightly larger, so it should make better torque, but it also has a much better intake and much better flowing heads stock. 

I believe the LS3 makes a better starting point as it will make more power and be easier to drive day in and day out.

Of course if you already have an Ls1, there is always the option of going to Mast Small Bore Ls3 Heads.  I read they are making some really good power using them!

Re: LS1 or LS3? looking for advice, 1979 Trans AM
« Reply #16 on: December 29, 2017, 05:45:07 PM »
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