Howdy,
Let me tell you my experience. I have a 1986 regal with an lt1 with iron heads and a 6 speed. The car has the a/c system in place, power brakes, power steering. I did the ls1 brake swap which added 3/8" each side to the front tire width. I installed 5662 in it as well as g-body cargo and the car sits higher than i would like. I removed a third of a coil off the front springs and it is still too high for me all the way around, but i need to keep the car at that height because i run 245/45 17 tires and i will get just the slightest rub on the front fender lip at higher speeds when i hit a bump. To be honest, the 5660 springs are softer and would probably have put me right where i am now without having to cut the 5662 springs i have. You mentioned you still have the v-6 springs, what drivetrain and options are you running on your car? How low it is now, and how high are you trying to raise it?
Mike