Pontiac Motor Swap Help Needed

I'm looking to do a swap of a 55 Pontiac 287 stratostreak motor into my 41 Pontiac. Has anyone done this type of swap? What motor mounts to use etc. Are there ant swap kits available. Any help would be greatly appreciated. Thanks

 

Since '55-'58 Pontiac engines have no provisions for side mounts, you'll have to come off of the front. Hurst made a saddle mount for '55-'60 engines, similar to the SBC saddle mount, but they have been out of production for many years. What transmission are you using?

 

Actually, my next question to post was going to be what transmissions will fit this motor. I'd like to go with a turbo 350 rather than have the 55' hydromatic rebuilt.

 

You can't bolt a modern automatic to a '55-'60 engine without the help of an adapter of some sort. You can use any of the G.M. 4 or 5 speeds with a '58-'60 standard shift bell--the '55-'57 bells were set up for the strange "selector" type three speed, like Buick and Olds used in the mid '50s. Any '55-'60 stick flywheel will do, but I believe the '55-'56 'wheels are drilled for a 10 inch pressure plate.

 

Would the 41' Pontiac 3-speed bolt up to the 55' Pontiac V-8?

 

There's a good possibility of it. Is your transmission in a position that you could give me some measurements of the bolt pattern? I've got a '55 stick bell housing that I can compare it to.

 

Unfortunately, both cars are in storage at my Dad's place right now. I'll see if I can get those measurements this weekend and I'll pm you. Hey, would the 55' crank be drilled for the pilot bushing since its currently mated to the hydramatic.

 

I'm quite sure that Pontiac V8s were like SBC engines, in that they all had the provision for a pilot bushing. Tell you what--the next time I'm where the bell housing is, I'll measure it and post the measurements. Then, whenever you gain access to the trans, you can compare the two.

 

I'm with Heathen on the '58 up bellhousing ... the later transmission is the best choice. Shift linkage on GM selector equipped cars is never fun, and they have a howl in low gear that most people hate.
I'm in the middle of a '55 Chieftain 3 speed car now. The ball bearings siezed in the pilot bearing, destroying the clutch gear pilot surface. We have a '51 8 cylinder Pontiac trans. which externally appears identical as far as bolt pattern, linkage, tailshaft length and rear spline. The clutch gear is 1/2" too long, but same spline. If they're interchangable, I'll weld and resurface the '55 clutch gear, then install it in the '51 trans and have it going again. Otherwise, we'll have to shorten the '51 part. Lot of h***le, not much of a trans. The owner paid over $1000 to have the '55 trans OH'd about 3000 miles ago, and he doesn't drive hard ...
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Thanks, I'd really appreciate that.

 

Weird........Rocky said to stick with my 55 slant pan hydro and that's what I'm mating up to my 389.

Guess it's all a matter of opinion.

I thought the 55 had dog ears on the side that allowed it to bolt with side motor mounts?? My 60 does even tho its front mounted and gunna stay that way.

Pontiac's are gunna drive me to drinking..........I swear it.

 

They started casting side mount bosses in 59, however if you've got a sidemount bellhousing and mounts, there's absolutely nothing wrong with the stock front center mount. It's compact, can be bolted to almost any crossmember (stock, fabricated, or otherwise) with a flat spot in the right place, and totally negates any reason to run engine side mounts or a saddle type mount. I've run more than a few Muncie 4 speeds with these type of mounts, and although the transmission just hangs there, it's plenty solid for floor linkage. I can honestly say any problems I remember having with this arrangement were totally of the operator malfunction induced variety.

 

I agree - go hydro ! What I meant to say was, if you have to have a manual trans, then later is better ...
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Hope you got driveshaft loops !
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I've been thinking about it and I think I'm going to use the hydro.

 

You should. Rocky says its the better transmission.......and he wouldn't lie to me.......I leave that job up to everyother man.

I'm mating my 55 slant pan up to a 389....which will also run Tripower as soon as I get it figured out.
Dunno about that 287 tho. If you need parts, I've got loads of them.

 

Well, I plan on putting a 389 in my 55' so I figured the 287 would be a cool replacement for the I-6 thats in my 41' right now. Especially since I already have it and 200hp beats 90hp.

 

Sounds like my story............gunna put a 389 into my 55 and prolly drop the 287 into my roadster since I already have it.

What are you going to use behind your 389??

 

I haven't thought that far ahead. Once I have the 41' where I want it I'll start thinking about it.

 

Hey SS, if you get it done, let me know the details, since I've been thinking of the same thing.

 

Will do. I've got a pm into Rocky so hopefully he'll be able to enlighten me.