Properly set, and as long as the camshaft gives vaccum levels within the adjustment range of the can, every engine will benefit from a vaccum advance. In most cases, guys cant get things set up well enough, and they are plugged. It's just easier. Under idle, and full throttle, the vaccum advance does nothing. So on any car that spends a lot of time at part and/or variable throttle conditions, the vaccum advance will help with power, mileage, plug life, and keeping carbon and soot off the chamber roof and pistons.
