I have a 1979 trans am with a 301 non turbo and I am looking to do my first motor swap. I was wondering what all would need to be done to swap it with a 1971 or 72 Olds 455? motor mounts? adapter for tranny? Does anyone know if the shaker scoop would still fit? Thanks

 

Luckily the transmission mounting pattern is the same. It’s referred to as BOP for Buick Oldsmobile Pontiac. Unfortunately the transmission behind a 301 may not be strong enough to handle a 455. So think about getting a transmission along with the engine. Also don’t limit your search to those years. Any 455 from 1968 to 1976 would work.

 

You'll need a set of Trans Am 403 motor mounts

 

That is actually a fairly common swap. I bet you will find plenty of help on this.

 

Those years 455 are just what are available to me at the moment. What are your thoughts on an olds 403 and do you think that it would be better suited for the stock transmission I have?

 

Easiest swap because the car was available that way from the factory. But I'm not as worried about the transmission surviving the 455 as Kenneth is. TH350's are frequently paired with 455's and usually last quite well if reinforced a bit to cope with the added torque.

'Course if you trip across a good deal on them, for another easy swap why not go Pontiac 455/TH400?

 

I would love to but Ive been looking for a pontiac 400 for awhile but have not seen any near by for a fair price. I have come across an olds 455 and olds 403 and was mainly wondering how the 455 would fit. Does anyone have any experience with a 403 build?

 

Once you drive an Oldsmobile 455 you would get it. I say good call on the swap.

 

I hate to say this, but a T/A really wants a Pontiac 455, not an Olds.

 

The 403 was an option in '79 with the 350 THM transmission as the only trans for that engine.

I agree the Pontiac 400 would be a great option.

The 400 and 403 were the largest options in 79.

 

It was coded differently than the one that came behind the 301, leading me to believe it may have been beefed up somewhat for life behind the torquier 403. I don't know this for a fact, though.

 

I have found over the years that Pontiac 455's are not that common to find. And when you do find them they are not cheap. You might have better luck finding a Pontiac 350 or 400. For this project I'd suggest to get a complete long block so you get all the pulleys, brackets, etc.
Based on that I think you should give serious consideration to going with an Olds 350, 403 or 455. You can find complete long blocks for these at reasonable price.

 

I did a 455 swap into a 81 trans am years ago, that car was a blast!

Use 403 engine mounts. You are going to have to do some fabricating for the shaker to fit the hood. If the transmission is in good shape, put a shift kit in.

The car I was involved in had a mild Crane cam, performer manifold, 1 3/4 headers, 2500 converter with 3.08 gears. Bolt on a pair of sticky tires it went 13 flat. My buddy got the itch to go faster, soon it had more camshaft, more compression,3.73 gears, big Holley carb, then it ran 12.50s, but was t nearly as fun on the street. He then added nitrous, then it ran 11.70s.

I think he should have left the car in the 13.00 and just added the bottle.

 

The 455 is 0.9 inches taller than the 403.