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Discussion Starter #1
I pulled a matching numbers '67 firebird out of a barn the other week. Its a 6 cyl and I'm going to keep as much of the car in tact as possible. I have a 70's era pontiac 350 that I'd like to put in during the meantime while the 6 is getting rebuilt.

I'm new to pontiacs and their motor/trans combinations. If I wanted to keep the original two speed power glide in the car will that work with the 350? What route do I take with the flywheel/torque converter?

Can I also just buy '68 motor mounts since the 350 came out in '68?

If anyone knows Pontiacs like that, please reach out. Thanks!
 

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Congratulations. I love Pontiac's Camaro. My Buddy has a '68 Firebird with a 400 that I helped him rebuild. We've helped each other with a lot of projects over the years. What I do know is he never had much good to say about Pontiac's 350. Not necessarily bad, but I suppose was lost in the shadow of the ultimate hot rodding example that Chevy introduced back when which bore the same cu. in. # but could readily produce substantially more power.

What I do know, by the seat of my pants, is that 400 we built ripped - talk about torque! Just sayin, may be worth it now to get a 400 if you're planning to invest and hold onto the car - will also make it much more fun and desirable when time comes to sell.

Also, not that there won't be people here who appreciate Pontiacs, you will likely gather up much more from the Pontiac Gurus on a 1st gen Firebird site - I suppose that's obvious though and can be more interesting and even riskay to talk about Pontiacs on a Mustang forum. I've noticed that even the diehard Ford guys will let down their guard for a Pontiac now and then, despite being a Camaro in bird's "clothing."
 

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I'm pretty sure the Powerglide will bolt right up. The Pontiac 250 I6 is not a Chevy, it's their own OHC design. It uses the BOP GM bolt pattern. Not sure about the flywheel but the converter should work as well. HE's Hydramatic plant that built the 350, 375 & 400 transmission had a fire. To fill the gap Powerglides were built with the BOP by pattern for Pontiac. The 68 mounts should work just fine. Pontiac changed engine mount and starter location to the current style in 1965.

If the 350 is a 75 or later, it'll have very desirable heads. They will have "6X" on them. Pontiac had 7.5:1 compression on all of their motors in the mid 70's. They used the same 6X head for the 350, 400 & 455. They machined the combustion chamber volume for each size engine. Putting a 350 6X head on a 400 will give about 8.25:1 and about 9.5:1 on a 455. In fact that's exactly what Pontiac did for the late 70's Trans Am with the 400 engine. Used the 350 head on the 400 along with a little hotter cam for 220 hp.
 

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Discussion Starter #4
Awesome advice, thank you guys for reaching out. I took some basic measurements last night. The converter slides in with minimal play? But the flywheel doesn't fit and the bolt holes are larger. Any recommendations for a new flywheel?

This car is really just going to be cruised around in, basic city/highway driving. Should I be worried about blowing up that trans behind a 350? I will check the heads when I get home.
 

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I'm pretty sure the Powerglide will bolt right up. The Pontiac 250 I6 is not a Chevy, it's their own OHC design. It uses the BOP GM bolt pattern. Not sure about the flywheel but the converter should work as well. HE's Hydramatic plant that built the 350, 375 & 400 transmission had a fire. To fill the gap Powerglides were built with the BOP by pattern for Pontiac. The 68 mounts should work just fine. Pontiac changed engine mount and starter location to the current style in 1965.

If the 350 is a 75 or later, it'll have very desirable heads. They will have "6X" on them. Pontiac had 7.5:1 compression on all of their motors in the mid 70's. They used the same 6X head for the 350, 400 & 455. They machined the combustion chamber volume for each size engine. Putting a 350 6X head on a 400 will give about 8.25:1 and about 9.5:1 on a 455. In fact that's exactly what Pontiac did for the late 70's Trans Am with the 400 engine. Used the 350 head on the 400 along with a little hotter cam for 220 hp.

That Hydramatic transmission plant fire resulted in some odd vehicles. For many years the 5 GM cars remained as separate divisions. They shared some major things but others completely different.

Olds and Cadillac had similar engines. Odly the Olds Rocket was more advanced than the Caddy. Olds had the full flow oil filter before Caddy. Pontiac, Olds and Caddy had Hydramatic auto trans (in varietries). Buick had Dynaflo, Chev Powerglide. Powerglide and Dynaflow completely different. Also Chev small block was totally different from Pontiac yet the both offered fuel injection for 57. Buick had their own V8.

So as a result of the fire there were Powerglide Pontiacs and Dynaflo Olds.
 

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A lot of pontiac parts are universal. The Firebird is sooo much better than the Camaro for so many reasons.

Check out these:
firstgenfirebird.com This is for first generation Firebirds only obviously


& google PY Forums

PY forums is performance years and you will get ALL pontiac guys there for all years
 

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Nice GM product. The firebird was what GM gave to pontiac because the Banshee was not OKd by GM. They thought the Banshee would directly compete against corvette. They got the co-marketed firebird which they shared with chevy Camaro. I have a 1969 firebirdvert project with original 350 engine. Even with the 350 engine that car moves. I assume that you confirmed the engine to be original because of the engine vin, as Pontiac put partial vins on engines from 1965 on. I will be pulling it out original enigne and putting a 400 or 428 (I have both of these just beggin to go into one of my ponitacs lol) in it and storing the engine. I believe that the Pontiac 350/400/428/455 engine mounts will just bolt up on your v6 firebird. Date your engine. Remember that Pontiac went to the GM engine 1980. The powerglide should be fine. But you could find a THM350 or 400 for not much and have a 3 speed. If you have info on the engine, I can tell you a lot about it (heads, block casting and engine code stamp). You can also get a "build sheet" for the car if interested. BTW I assume you know that Pontiac 350 was the small v8 in late 60s but it was a powerful engine. Plus the car was pretty light. There were a lot of firebirds that were beating GTO. Another fun fact was that until 1970 Pontiac GTO and FIrebird could not have a engine bigger than a 400 because of GM fear of them beating the corvette!
 

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There were a lot more BOP Turbo 350 & 400s built then Chevy Turbo 350 & 400s built and prices reflect that. A TH350 would be an excellent choice over the Powerglide. It's a direct bolt in. Same trans mount, same length and same yoke along with a lower first gear and more efficient then the TH400. The Powerglide is lighter and more efficient . Then the TH350. Less rotating mass, uses less hp then the TH350.
 

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Discussion Starter #9
I've been looking for a TH350 and there might be one or two close enough to me worth checking out. Would a flex plate designed to be behind a 350 with 166 teeth and a 2.75 inch ID work?
 

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For fun make 5 parallel areas on a big chart.

Chevrolet
Pontiac
Oldsmobile
Buick
Cadillac

GM was always a collection of independent car companies. Not all that different from the merging of independents.
Pick a year at random. Say 1940. Chevy had OHV inline 6, Pontiac Flathead 6, Olds flathead 6, Buick OHV inline 8 with optional automatic, Caddy Flathead V8. In 49 Olds Rocket OHV V8 became the hot car. 55 Buick Century, 57 Chevy and Pontiac were hot.

Corvette seemed to be like for corparate symbol/advertising. Why and on what form would GM corp be concerned about the Vettle
getting beat (dragging, track race...what?).
 
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