Very few people that had 8.2 from OEM liked them. I see no reason to go to all the trouble of putting them into a classic. A 53 series will fit in a 55.2 and later without too much trouble. I'm not a Detroit fan and have run Cummins since the 60's. But at least the Detroit was built to be a Diesel and they last forever. My yard truck has a 53 series and all we ever do is fuel it and put in some oil ever so often.