84 301T

[tajoe]

Well people, the attempt is being made. I'm determined now to try and get at least one of my T/As on the priority list. I've put them off long enuff, while struggling thru life with balancing work and raising family duty's, along with everyday chores of maintaining and fixing the list of worn out possessions we all have. Nothing new, you've all been there.

Between the 4 vehicles I have, (83 C-30 6.2 diesel stick shift dually, runs but rotted out, 93 2500 also 6.2 diesel, my work truck right now, my 73 T/A needing...everything, and my 84, 305 TH700 T/A), the 84 has the best chance of succeeding. The body is pretty good, with no rot, and the interior is tolerable. It had been garaged most of its life, but the tranny went away, and that's when I inherited it. Altho I've owned it for close to 10 years, I've never had it registered or driven, due to the tranny. I've kept it waxed and covered, with some of those years being stored outside. It has shown a bit of deterioration, but nothing that can't be cleaned up. So the 84 has the 1st nod.

Many people are probably saying, "Why put the 301T into the car? The chevy motor has more potential," or "Why ruin the originality of the car, by bastardizing it"? Or "If you're a Pontiac fan, why not a 400, or 455?" All are legit and accurate opinions. But for me, my reasoning is, I already have the car, and the engine. I'm not looking to be the fastest, or most powerful anymore. Those days are behind me. Plus the retirement finances have to be taken into consideration. My goal is to put together what Pontiac wanted to do in 82, but was squashed by GM. I won't make it the way the government would've mandated the car be built, with emissions, and all the other corporate restrictions, but something close enuff to resemble what a gear-head would've done to the car, to make it a little better performer. We all know the limitations of the little 301T motor, and I plan to do some up-grades to it, at some point in time. I love the fact, the power-bulge hood is functional, and the 301T places the QJ right under it, the way it was intended to be at Pontiac. But in the end, I would like the car to at least run 14s at the track, and would be thrilled if it'll touch the 13s. And because the 80-81 cars were so God awful heavy, and strapped with an automatic, 3.08s, and emissions, I think those numbers are do-able W/O lots of performance mods. Besides, the 84 is almost, (if not) 500lbs lighter. And with a T-5, and better rear gears, it's gutta help.

So, with all that being said, I have done a few things since spring, and am in the middle of figuring out the hydraulic clutch system. In a bit, I'll post some pics of where I'm at, and hopefully some of you might enjoy it. But please be patient, because, I'm still working for a living and "free" time, isn't so available. More to come. 

[b_hill_86]

I like it. Something different for the sake of being different. Kinda like one guy I saw that put a 400 in an LS 4th gen if I remember right. Good luck to you and I’ll be following along!

[hakitup]

I like the idea, looking forward to seeing progress.

Tom H

[tajoe]

Hello Brian and Tom, so B4 I get back out there to the garage, I'll post a few pics for the interested.

In the 3rd gen category, I posted just a quick blurb about swapping the P/W regulators, over to mechanical ones, due to both motors blown, and no battery. So for years, I've been worried about water getting into it, because the RHS window was down an inch. Always had it tarped, and car covered, and have kept the water out, but it doesn't breath well, under a tarp, as we all have learned. With the mech, regulators, it's so nice to be able to crank the windows up and down at will, W/O the need for electricity. And even tho the car came with P/W, I swapped out the grey interior many years ago, that was all beat up, and found a salvaged car with a beige color interior, that I installed, to clean it up. But the donor car didn't have P/W. So the door panels were cut for cranks, which I left in place, to keep the holes filled. Now that I own it, and am not a fan of junk window motors, and problematic switches, I can now use the available window cranks, that have been un-functioning, after all these years. The old reliable mechanical regulators work fine. The donor car even had a stick shift, and I was able to confiscate the pedals, and console when removing the interior, so I now have the right console for the T-5, and no holes for the P/W switches.

I wish I had enuff fore-thought to look at the clutch system. (Maybe I did and forgot). Not sure what yr the car was I scabbed from, and don't remember if it had a mech.  Z-bar linkage for the clutch, or hyd. That's where I'm at now, and will share some photos when I get to a good point. My "biggest" concern now, (and might need some help from you guys), is whenever I try and post pics here, I get error codes. So I'm gunna run a test right now, and see if I can post something. Here goes.

[b_hill_86]

I can agree with the power windows thing a bit. I have them in my 77, and they do work ok, but I almost wish I just had manual.

[tajoe]

I just spent 15 mins with a reply. After writing, I attempted to load a pic from my computer but the error code said, "file too large". So I went to PB, (as I just did above), and loaded a similar photo, and once again, the site wouldn't let me post it. Said it was too large. (From Photo bucket). It just took one this morning. And to top it off, when I went back, my post was erased. Not very happy right now. <-(Gee, at least I can show one of these stupid little guys)

[b_hill_86]

I’m not super familiar with photobucket anymore. It’s been years since I’ve used it. As for your issues, I don’t have an easy answer either but I’ve experienced the same thing and lost posts I gave up on. What I try now is to make my post without the picture then go back and click modify and try to add the picture. Only thing I can offer is there is a size limit of trying to add directly to the site and at least on my iPhone, it allows me to choose a size (sometimes) when I’m adding it. Not sure about other phones or computers off hand.

[ryeguy2006a]

I love this idea for the powerplant! Love seeing projects with clear goals! One thing I've always wondered about these engines is specific to the turbo. Has there been any kind of development for a modern turbo replacement? Or at the least upgraded impellers? I know that the engine's have their limitations, but I'll bet you could significantly improve efficiencies with the motor.

[tajoe]

Joe is the guy here with all the good stuff, and he's also with the 301 garage forum that has all the specifics on this engine.

https://ttaperformance.com/

[tajoe]

Got the clutch master cylinder mounted yesterday, and I can think of 100 things I'ld've rather done. Such as had my fingernails, and toenails all yanked out, one at a time. Not fun being under the dash, with limited space. I'm gunna do a test...(again), and see if I can get a photo to post, "W/O" an error code. Here goes.

And now, to try another, and add it here.
So far, so good...maybe. Now to try and post.
Hey, how sweet it is.
Now to explain the pics.
The system above, is a third gen stock one, with all the parts. The white plastic reservoir, bracket, and hose, to the M/C and pedal rod, and finally the hose going to the slave cylinder. The fork pushrod, and boot is not in the pic, but it is here.

I've tried for weeks to find some-one (on the other brand X forum), who knew exactly how, and where to place this M/C, but came up M/T handed. There were a couple that had some info, but wasn't pertinent to my application. (they had alternate or aftermarket parts). And I wasn't sure if my pedals were correct for the hyd. system, thinking the linkage hole in mine was for a manual set-up. So I "too" had-ta start from scratch, to locate the center of the M/C.

-I started by measuring the distance of the stock M/C and rod, in the extended position, from the hole center, to the firewall flange. Approx 9". (I also pushed the rod in, just to see the travel. Approx. an inch)
-I then cut a piece of 5/16ths threaded rod, bent 1 end on a 90°, for the pedal connection, and cut the rod a couple inches short of the firewall.
-If you'll notice in the pics above, you'll see a white tube, with the rod in it. The tube is 1" PVC, which I copied the same angle the MC flange has, and cut the tube to the same length as the M/C.

Previously I had used another rod, the same length as the extended M/C rod to the firewall flange, and used it as a rough guide to where the hole center on the FW should be. By placing it in the pedal hole, and moving it into position, I marked an X on the F/W. This is now where the white tube is taped to above. (The tape is only there to hold it up, for photo purposes. Can't hold it, and take pictures, at the same time)
The masking tape tied around the rod, is to show the engagement of the rod, into the M/C tube, while in the fully extended position. Then I shove the pedal to the floor, and remarked the rod with tape, to show the amount of travel the rod will have. It was just at an inch, which is how much is in the M/C. "Theoretically", it should work.

[tajoe]

Next came a cardboard template of the M/C flange, to locate the holes on the FW. I know it's not professional, but neither am I.

Once I drilled the flange holes, I marked the center, (and confirmed my previous marks) then used an 1" and a 1/2 hole saw. the FW is made of tin, and it went thru easy. (Another concern to be addressed later)

Altho it looks real nice, of course it need some die-grinding (about a 1/4") with a carbide burr, to "adjust" the fit.

[tajoe]

If you'll notice in the pic below, the M/C needs a clearance "dent" that was already provided by the factory, (under the hood) in the wheel well.

With the temporary bolts in place, the M/C was resting on the metal of the wheel well, so I had-ta hog  out the hole centers a bit to the pass. side, to clear it. Once in place the alignment was pretty good, but will need a bit of finesse at final assy. All this is preliminary fitting, with the finale test being the system actually disengaging the clutch.

And in this last picture below, if you can see the silver nut and bolt holding the pushrod into the pedal. I litterally spent an hr trying to get it into place. With all the surrounding obstructions, it was an absolute nightmare.

[tajoe]

So that's where the car is at, at this point. I can't believe the engineers put this M/C on the angle they did. My guess, is because everything is so tight on the firewall, they had no choice? I know it wasn't for efficiency of design, that's for sure. But the pedal does move the pushrod a full inch, even with the 45° angle. I would've preferred a more direct placement of the pushrod, but it's just not possible.

Next is to pull the motor, and start fitting mounts for the Pontiac.

[5th T/A]

As others have said, I like the idea of putting a turbo 301 in your 1984 TA. This is what Pontiac would have done if GM didn't pull the plug on the 301. This is why early 3rd Gen TA's had the offset hood bulge. Obviously, when Pontiac built the 301 T, they were at a disadvantage not having modern electronic controls for engine timing, fuel flow and knock detection. Since my car came with a NA 301, I tried to join 301 Garage. I always got a message saying "registration is disabled". Regardless, they have a lot of good 301 information. Joe from TTA Performance is the guru on these turbo motors. I think he has a streetcar running 12.80's on ethanol without going into the engine.

Hang in there, I would love to see this project finished!

[FormTA]

I love this! Can't wait for more. I love unconventional builds. This is going to be cool and real Pontiac guys will get a kick out of it. You have to advertise the 4.9 turbo somewhere whis an emblem too!

[tajoe]

Hey guys, glad to see you're interested. 5th, sorry to hear the garage won't let you in. wonder why? I know the site has been around for quite some time, but don't think there are a lot of us who actually know about the 301 mill. I'm sure they're getting scarcer by the day. I'm just glad that Joe R. is still keeping the website alive.

And Luke(?), I plan on putting the 301T badging, just as it should've. Probably will do the paint theme of the 81 T/A car. Even wanna use the turbo hood bird, just for that "retro" look. The hood is the same width, but the length a little shorter on the 84.
(Wonder if I can post a photo of it?)


This 81 maroon, and gold hood chicken just..."make my day". It may take a bit of trimming, but think it can be done.
I know I have a "long way" to go, but hey, you gutta have a dream, right?
I'm taking a personal day today, and had a bit of time to post on this thread. Hopefully I can get the motor out soon, to show some progress, but also have other household "duties" that need attention. Trying to balance it all. Hang in there men, and thanks for the inspiration.  I now have-ta get in the cellar, and work on my oil fired furnace. "B4" I need it.

[roadking77]

Im glad to see a third gen getting a little love. They are my favorite as far as body design goes. I particularly like the ones with an aero skirt, i.e. your 84. Was that an option for that year? I thought 85 was the first year that they came stock that way. I had an 82 firebird and an 85 trans am, def will be following along with this one.

[tajoe]

RK, I "too" am a fan of the body design of the "early" 3rd gens. 'Specially like the power-bulge hood. (With the QJ under it.) Other pluses are the elimination of a quarter ton of weight. Not a fan of the drive-trains tho. How-ever, because the 301T isn't know to be a tire shredder, (and the fact I won't be driving it that way), I think with the T-5, and the torque tubed 10 bolt, it will all balance out. With the areo-dynamics of the body, and the 5 speed ,and a decent set of gears, I think it'll be a fun streeter.
As for the ground effects, I'm still not savvy on these cars, but I do believe the pkg started in the 84 model. At least I know this car is all stock. Not sure about it being optional or not. Thanks for chiming in.

[kentucky yeti]

That picture of the maroon body and gold hood bird look perfect for each other!

[roadking77]

I think that combo will be perfect. I too have no desire to race, as long as my car gets along with traffic I am fine. I am a minority in that I dont think a car needs 700+hp. I have not 'studied' the third gen, just remember them well when they were new. The 82 and 83 had really small flares in front of the tires, I dont remember much of a front air dam. The 83 Daytona (my dream car,lol) had an aero package similar to what is on your car. I thought the 84 had the same as the 82 and 83 and what your car had was an upgrade, I could be wrong with that one though. 85 was changed altogether and was a bit bulkier, but looked great. I think 84 was the last year for the bulge hood as well. 85 the whale tale was an option, I think the flat deck spoiler like on your car was gone by 86 along with the addition of the third brake light. Sorry, for the rant.

[tajoe]

That picture of the maroon body and gold hood bird look perfect for each other!

I thought so too, Mike. I've always wanted a maroon GTO, with a white interior, but has never materialized. This 84 has the saddle color interior, and with this (81 only) deep dark rich maroon, (forgot what Pontiac called it), think the combo still works. But once again, got a "long" way to go B4 getting there.

I cleared a hole in my garage, and dug out another eng. stand, so now I have a place to put the anemic 305, when I yank it out...next. Rather than trying to stuff the complete 301T motor to fit the mounts, think I'm gunna drag out either an empty 72 455  block, or a 73 400 block, to compare the eng. mount bolt hole locations, to the 301 motor. Not sure if there's a difference from 1980, to the early 70s. My last 557 block went away, but I really don't think there's a difference. But I need-ta check, just for my own piece of mind. Figure it'll be easier to maneuver an M/T block on the K frame to align the mounts, rather than an entire eng.

I think that combo will be perfect. I too have no desire to race, as long as my car gets along with traffic I am fine. I am a minority in that I dont think a car needs 700+hp. I have not 'studied' the third gen, just remember them well when they were new. The 82 and 83 had really small flares in front of the tires, I dont remember much of a front air dam. The 83 Daytona (my dream car,lol) had an aero package similar to what is on your car. I thought the 84 had the same as the 82 and 83 and what your car had was an upgrade, I could be wrong with that one though. 85 was changed altogether and was a bit bulkier, but looked great. I think 84 was the last year for the bulge hood as well. 85 the whale tale was an option, I think the flat deck spoiler like on your car was gone by 86 along with the addition of the third brake light. Sorry, for the rant.

700 HP would be fine, if you were at the drags, with slicks. On the street, there's only so much you can get to the ground, even with modern tire technology. I'm not a fan of this "lets race, from a rolling start, at 50 MPH". And then explain that one to the officer in the un-marked car, and the Mrs., why you lost your license going over 100, and your ins. company now drops you. I don't mind a little "spirited" driving, but with HP over 400, it's pretty easy to get into trouble. And if you're not gunna use it, why spend the money on it? To each his own, I guess.
And RK, you mentioned a "Daytona" package in 83. That's how much I know about these 3rd gens. Don't even know what that car is. I'll have-ta Google it after. But the Power bulge hood did continue after 85, (I believe) but think they were only used on the Formulas, not the T/A. Maybe (?)

[tajoe]

B4 I go any further, I just want to "document" what I did a few weeks back. Just to get it listed in my "up-grade". Because the 301T down-pipe is a close fit in the chassis, I decided to remove the AC system off of the car. I know the southern crowd won't be pleased, but here in New-England, there's not much of a need. Not like the south anyway. It does get hot here in the summers, for a few weeks, but I'm use-ta not having it, so I would rather have the room under the hood, and less weight and maintenance. Besides, the car has T-tops, that I don't plan on doing away with.

Always cracked me up that chevy went and put their compressors on the drivers side, and had-ta route the hosing to the evaporator on the other side. Lots of un-necessary lengths of hoses. I had already purchased a std blower housing years ago, and decided to dive into removing the existing evaporator, and installing the heater housing. All in all, it didn't go too bad. (Much better than that obnoxious hyd clutch M/C) And it is so much more accessible back there now. Will have-ta make the connections under the dash, and temp. control panel at a later date.



I know none of it is pretty. but for the time being, just trying to get everything fitted. The bottom pic looks so much better with the removal of not only the evaporator, but the hoses and compressor too. I haven't hacked anything removed from this car, and am boxing all the junk up, for.......? (I have no clue why. I'll never use it.)

[tajoe]

Yesterday, I took some measurements from the 72 455 block, and compared them to the 80 301T block, and find that the mount holes are the same pattern. As a matter of fact, the 72 has "2" provisions for mounts. I'm guessing the other set is for a full size chassis, and not just the A, or F bodies. But the 301T only accepts one mounting.


Next, get the 305 out, and fit the mounts, using the 455 as a "template" only. Once I get the mounts on the K-frame, then I'll drop in the 301, just to see what it looks like.

[TATurbo]

Congrats on getting your project moving! I'm interested to follow along too. 
I'll be honest, the early 3rd Gen's are my least favorite  F-Bodies.  That said...I love the idea of installing a 301T under the hood...It's gonna be very cool!
When I first bought my 81 Turbo it had a rebuilt 301T that the previous owner said 'had some work done' to it.   That engine ran really weil and it pulled very nicely once the turbo got spinning. And, the turbo sounds...Ahh...music to my ears.  The Pontiac 301T was good enough to get me hooked on, turbos back in the day.   

Here's a pic of the engine that was in my '81 when I bought it in '90:

TA-Turbo 301 Turbo_zps3rpl2wdy by Tom Sherer, on Flickr
 
Good luck!  I'm looking forward to following along. 

[scarebird]

Why not use the 301 mounts?  they are the superior clamshell type.

Test fit the 301: mark or tack weld the lowers to the subframe, remove the engine and bolt right to the frame.

[Jack]

 I haven't been on TAC for a while but I'm glad I logged on today and saw this. I'm very excited and happy to see you doing some work Mr. GTO, I just need to find the time and read all of the posts and follow along 😊

[tajoe]

Why not use the 301 mounts?  they are the superior clamshell type.

Test fit the 301: mark or tack weld the lowers to the subframe, remove the engine and bolt right to the frame.

Absolutely SB. If you'll look at the photo above, (of the nasty dirty 301T motor), you'll see the mount brackets still on the eng.
When I pull the 305 out, I'm "hoping" the 301 will drop onto the factory location of the SBC mounts. I've taken some really crude measurements, and they look very close. Remember, there's only a couple years difference from the motor and chassis, so what are the odds of it bolting onto them, with no mods? (Probably not very good). There have been a few people who have popped these Pontiac mills into 3rd gens, and I know quite a few talk about adapters, re-locating, and rewelding, and other ideas, but I don't know. I know for a fact, the eng. brackets fit right on the 84 T/A mounts. But the mount location on the K-frame may have to be altered. Time will tell. I'll keep you guys posted, cause it won't be too long, when I yank the SBC.

I haven't been on TAC for a while but I'm glad I logged on today and saw this. I'm very excited and happy to see you doing some work Mr. GTO, I just need to find the time and read all of the posts and follow along 

Howdy Jack, glad you're back. Sucks, working for a living, don't it? Who ever invented this system anyway? They need-ta be shot. Thanks for the moral support, and hopefully you can get back into yours soon too. Someday, I hope you, your sons, and I will be cruising with our F/Bs together. (Before we're all suckered into mandatory EVs

[scarebird]

Why not use the 301 mounts?  they are the superior clamshell type.

Test fit the 301: mark or tack weld the lowers to the subframe, remove the engine and bolt right to the frame.

Absolutely SB. If you'll look at the photo above, (of the nasty dirty 301T motor), you'll see the mount brackets still on the eng.
When I pull the 305 out, I'm "hoping" the 301 will drop onto the factory location of the SBC mounts. I've taken some really crude measurements, and they look very close....

It should not - SBC mounts are mounted forward on the engine - BOP in the middle.  I made a point to mount the L84 in my 71 middle of the block so I can pull clutches, etc without supporting the engine.  Note the 3 holes forward on the crossmember - those are the "old school" Chevy mount holes.



https://forums.maxperformanceinc.com/forums/showpost.php?p=6328227&postcount=46

[tajoe]

Man! Look at how nice and "clean" that frame is. (I'm envious)
So what frame and motor are we lookin at here SB?

[scarebird]

A couple years ago I did a frame off of my 1971 Lemans Sport.  The frame was blasted, rewelded in some spots then powder coated.  A better shot of the frame - note the two different mount hole constellations.



I am putting in a 2020 L84 (5.3) crate motor.  This was refitted with a LT1 cam and AFM delete kit.  Still has the VVT and of course direct injection.  This is coupled to a Tremec TKX and hydraulic clutch.  Motor Trend dynoed the stock unit at 400 and gets excellent mileage.  My 2016 Sierra has the older version and does quite well.

https://www.motortrend.com/features/5-3l-l83-dyno-test

[Wallington]

I'm all for something different. I thought every household in the US already had a spare SBC in the shed, that had seen use in 3 of their previous vehicles.

[tajoe]

i thought the same thing Walley, about the SBC. Until I had to do work to a 76 C-10, W/ a blown up 350. Trying to find the most basic of stuff to get it fixed, (Even freeze plugs, or something as simple as VHT chevy orange eng. paint) wasn't as available, as you would think. LSs is the new SBC. Pontiac V-8s? Are starting to thin out too, so even the lowly 301 is gaining some appeal. At least with us Indian loyalists.
Now to get out in the garage, and start yanking this 305 out. Can't wait to check the fit of the 301 to the K-frame. Pics to come.

[Jack]

OK I'm all caught up and waiting like a kid at Christmas for your next post

[tajoe]

What did they use-ta say, Jack? "Week-ends were made for Michelob"? I'm glad you're recuperating, after a long hard week.
Got the undercarriage unbolted last night, and was able to take some "better" measurements, and like scarebird and others have already confirmed, the mounts "are" in a different location. Surprisingly (to me) the chevy mounts are farther fwd, (almost 14" from the rear), where the poncho location is only about a foot. So I'm hoping the bolt hole location is already pre-drilled on the K-frame, where I can move the chevy mounts to. Both the Pontiac and chevy mounts are about 4" in length.  Hoping, (between chores) to get the 305 yanked out today. Tomorrow, (Sunday) I have obligations to an outside car show in Manchester, Ct with a buddy, so I guess I wont be progressing much on the 84. Well see how it goes, weather wise.

[tajoe]

"Out with the old, and "in" with the new". (Or soon to be anyway).
The 305 is no-longer, and luckily it looks like the frame is already pre-drilled, to move the mounts back for the Pontiac. I'm not looking fwd to unbolting these mounts, cause I believe the nuts on the under side of the frame, "aren't" very accessible. Of if I'm remembering right, on the 2nd gens they're a pain to change. Wondering if the lower A-frames need-ta be removed.


In the lower photo of the mount, you'll notice the oval hole just to the left of it. If the other two holes have that same configuration, "maybe" it'll fit. Now I need-ta fix my pressure washer, (with a busted pump) to get the eng. bay cleaned up.
(Notice the slave cylinder dangling down next to the mount). It'll be fun trying to bracket that to the BOP bell-housing.

[scarebird]

The Pontiac gods are smiling.

[MNBob]

Ditto above.   Always a milestone getting the old one out.

[tajoe]

Back from the Manchester car show, and had a few minutes to play in the garage.
Next step is to get the mounts laid out. Yesterday with the motor out, I was able to confirm the Pontiac 301 block mounting is approx an inch farther rearward than the chevy. I could see some extra holes around the chevy mounts, and was wondering about pre-drilled holes that might line up, a little more rearward. But I also needed to know if there was a height difference between the 2. Trying to get an accurate dimension, comparing the 2 engs was difficult because you can't get a straight shot with the tape measure, cause you have-ta go down and around the oil pan. And eyeballing centerlines from the front, doesn't work either. So I decided to use the "plumb bob method, and drop a couple lines from the mount holes in the eng. brackets. Kinda looked like this.

And by checking both the same way, it appears the Poncho is approx. and inch closer together, meaning the frame mounts, need to be lowered a bit.

[tajoe]

Because the old mounts need removing, (and probably replacing), I got back under, to see how much of a bear it would be, to get at the nuts, inside the K-frame. And it don't look pretty. I have 3 photos to show, where any kind of access to those nuts would be. There are 2 that are feasible, (not easy, but doable), but the top fwd one doesn't look promising at all. It appears the best way, is to remove the springs and lower A frames.  In the top 2 photos, if you look in the hole, and inside the rubber A frame bushing area, you can just barely see the nuts inside. But the last one shows the spring pocket, that is where the fwd bolt is, and practically impossible to get any tool in. So next, will need to remove the A-frames, to access the nuts, to remove, and redrill the mounts.
 


I wish I had a crayon, so I could circle the nuts in the photos, but I always have a hard time doing that. Hopefully you can see them. They're practically centered in the photos.

[scarebird]

IIRC 3rd Gens only had 3 basic motors in 1984: 2.5 four, 2.8 V6 and the V8 305.  I would bet the other holes are for the V6 mounts. 

That said, you will be needing to drill new holes anyway. 

What I would do is make a pair of 0.250 thick plates that match the 301 clamshells; send-cut-send can make these easily. 

The holes would be countersunk to take 3/8" flat head bolts where the heads are welded up.  This would be a stud plate.  Fit up the clamshells to these plates then bolt up to the block mounts.  Drop in and bolt up the engine to the trans temporarily and tack weld the plates.  Remove the 2 slider bolts, pull the motor out then stitch weld the plates directly to the frame.

oh, and the existing mounts?  just grind the bolt heads off and remove then grind the paint off where the mount plates go.