86 Pontiac "2+2" Gran Prix

[vintageracer]

I've got a nice 86 Pontiac "2+2" AeroCoupe Gran Prix. I want to change the springs to lower the car and mount 17 or 18 wheels/tires on the car.
Since this car is a "G" body, can anyone recommend a good spring to drop about 1 1/2-2 inchs since these cars sit very high stock? Second, what size/offset wheels/tires will work with the recommended springs.

I woulld like at least 9 1/2 inch wheels in the back and 8's in the front.

[Jimmy Sean]

This may be of some help to you.

http://home.earthlink.net/~bzdel/TireWheel.htm

[Bill Howell]

Mike,
I think 9 1/2 wide is going to be a stretch. The body and frame both get in the way in the rear. I have read somewhere lately about 9" but that is going to be about all you can squeeze under it. I can tell you that the malibu had issues with 8" on the front also. I had to get a different offset for the front. When you get here for the shades, I will let you look at the malibu and see what you think. I wish it set a tad lower but not going to change things again. Also it has only been together for 2 months, so maybe it will settle abit more.
8" with 4" bs is fine on the rear.
8" with 3 1/2 on front

[vintageracer]

Thanks for the link.

[Supercharged 86]

I have 255/40/17 17x8 wheels with 4" BS all around. My front lower control arms may be a little shorter than stock because they're Spohn adjustables and I adjusted them all they way in to make it work with 5660 springs. I've seen 8" on the front and 9.5" on the rear and supposedly it fits well with a 275 tire, but the car wasn't too low. Check out the Member's Rides section of elcaminocentral.com and go to jims78elky in the 5th gen section to take a look. Check out bubbadrift.com too. They're running 255s up front and I believe 275s in the rear.

As for lowering, I'd just cut the springs for the easiest way. It would be better to use a higher rate spring so it's less likely you rub you new wheels and tires.