Once you get in the 450+ cubic inch range one is thinking torque instead of horsepower. We have swapped a 455 Buick and both a 472 Cadillac and a 500 Cad into AD's but the only 455 Olds I recall went into a 51 Ford pickup. Also a 455 Pontiac into a 48-50 Ford pickup. What you will find is in a pickup the tires that fit inside the fenders ( 10" ) will go up in smoke in any gear at under 30mph. A no weight on the rear truck has it's limitations and if you do rear frame and fender modifications to use a very wide tire the truck is helpless on wet pavement. A very shallow rear gear (mid 2.00 range) will help to pull some of the beasts teeth but IF you break tires loose with a shallow gear you REALLY make smoke. As far as Olds speed parts go the bible is Mondello. Has everything including advice.

Evan