I have an opportunity to buy a 455 out of a bonneville. Anybody know what (if any) modifications I will need to do to get it to fit?
This is a very simple swap. Since 1967, all Pontiac V8s have the same external dimensions, and will readily swap parts like intake manifolds, timing chains, and oil pans. The exception is the much maligned 301. As another list member mentioned, the Feb. 2001 issue of Car Craft has a brief article on swapping a 326 for a 455. It contains some good photos of the differences between the 1969 and earlier motor mount bosses/holes and the 1970 and later version. There is also a good description of water pump and pulley issues that need to be addressed. The article would apply to those of you with 350s and 400s as well. But, essentially, the easiest way to do the swap is to take the timing cover, water pump, pulleys, and accessory brackets off your present engine, and transfer these to the 455. The same applies to your exhaust manifolds. Now the 455 will just bolt into place like it grew there. Some other issues not mentioned, or only lightly covered in the article are: -Flywheel/flex plate.
