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Discussion Starter #1
I want to put a big block in an 82 Pontiac Grand Prix. It has the 4.1 v6 in it, original motor.

I have chevy big blocks readily available, but i was wondering if it would be easier to put in a Pontiac big block, like a 400 or a 455. It would also be good to have the chevy in there because of the transmission choices...

anyone know what this requires or where I can get conversion parts

I picked up the car for $200 and want to have a little fun with it

Thanks
 

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Hates: Liver. Loves: Diesel
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5,659 Posts
The BBC will be cheaper, but that car should come drilled with all possible motor mount holes and configurations ready for whatever. The pontiac engine technically died in 1981, but the holes should be there for it. Should be as simple as buying the right motor mounts and dropping whatever GM engine in you wish... except Caddy, but MTS and other companies make swap mounts to fit the 500 in it.

BOP trannys are pretty easy to find these days. Getting a little more scarce, but not bad. I have a freshly rebuilt TH400 BOP tranny with exactly 27 miles on it sitting here without a tail housing. I could be convinced to sell it :) You would need a TC, and a tail housing, but it has a deep cast aluminum pan on it.
 

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Ive done the bbc swap before. it is pritty basic, Just get the mounts for a monte carlo with a sbc. Then set her in, all the brackets you can get for a 77 chev burb with a 454. If you want to run the AC then you will need to run the stock low profile valve covers. If you have no ac plans then just ditch the ac box and use a non ac box. A th350 is a direct swap for trans mounting.
 

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Ifit aint fix...Don't broke it
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swap

If you want to run the exhaust inside the frame you will have to bump the stock mounts up between1 1/2 or 2 inches otherwise you will have to flatten :smash: the pipes off the the stubby headers. The stock low flow 80s model truck exhaust manifolds will solve this problem but they weigh a ton and restrict flow. The ac box is in the way and you might have to trim and patch it a little for some clearance some are okay some aren't and it also depends on valve covers etc....Good Luck you Effort will be rewarded :evil: (Until the first trip to the gas station :p )
 
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