I just answered a similar question on Missing Links, but I answered it in terms of the engine and not the compartment. I am almost positve that the M60A1 engine compartment is the same as the M60A3 hull. It has been about 15 years since I've had to pull the pack on an M60A3 and even longer ago (20-21 yrs?) that I pulled the pack on an M728 CEV (based on the M60A1).
Basically all the M60, M60A1, M60A2, M60A3, AVLB, CEV and M48A5 engines are interchangeable. The engine series went from AVDS-1790-2C to -2CA, -2D, and then -2DA as improvements and modernizations were made.