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Welcome to FBN ! :welcome500:

All the Pontiac V8's from 326 thru 455 are the same size, on the outside. So, as long as you have the Pontiac V8 frame brackets for the motor mounts, any 350, 400, 428, 455, and others, will bolt right in. :yes

And, as you mentioned, a stout 455 will break stuff, if you have sticky tires. You have your Bird listed with an auto trans. That is one of the items the 455 will break. It must be beefed up, with stronger intermediate sprag. If it's a TH400, you'll need at least a 34 element sprag. If it's a TH350, you'll need either a 36 element sprag or a spragless unit. If you go with a 200-4R or 700-R4, they will need extensive upgrades, to survive.

The stock 8.2" rear end is likely the next thing that the 455 will eat. You need either an 8.5" or a 12 bolt. The cheapest is probably an 8.5 out of a 2nd gen Bird or Camaro. But, since the springs are further apart, the spring perches must be moved in some. An 8.5 out of a '71 -79 X-body, (if you can find one) is said to be a direct bolt in. But your driveshaft will have to be slightly shorter, I think. This has been a very popular swap, for 1st gen Birds and Camaros, for years. So, in some areas these rears are getting real hard to find. :(

Now, having said all that, I'll add this. If you just run narrow, hard rubber street tires, you may be able to get by with a stock trans and rear, for a long time. We got by with a Buick 8.2 for part of a season, in a '68 bracket Bird. But, then, one night in Tyler, TX, that 455 broke the the rear end and oiled down the track. :( That same 455 had already ate the stock sprag in 2 TH400's.
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