i dont know the exact numbers on them right now. i am off at college tryin to get some ideas or tips. when i get around them again i will post the numbers. they are used the guy who i got them from used them with a blower. i am trying to put together a 512 ci bbc with about 13.5 compression ratio car is a 1985 buick regal. i want to run 9 seconds with a hit or two of juice. the block i a 2 bolt main it comes out a 1991 chevy dully work truck.