500 AVS2 or 650 AVS2 ???

Hysteric said
A modded 600 only pulled 1.2 or 1.7 inches at the top end on a 360 that ran mid 12's

My point is why guess which to go when you can measure what you got and make a more informed decision.

1.7 is fairly restrictive so can be 1.2 depending on application. Pumping loss can kills hp, mpg etc.. also.