Year One has their cast aluminum Rally II's. Opinions on 17"x8" or 17"x9" or staggered with 8's up front and 9's in the rear. I am going with a Ride Tech coilover package with the 2" drop up front. Possible sizes for these? I was rolling on 15"x7's with 255-60R-15's.

Have you mini-tubbed your GTO? If not, an 8" wide rim with a 4.5" backspace is about as wide a rim as you can get under the stock rear wheel wells. A tire/wheel measurement tool may prove me wrong. However, the late Pontiac Historian John Sawruk told me that an 8" rim was the widest rim Pontiac ever put under the 2nd gen A and F bodies - for a reason. 6" and 7" rims were the norm.

I have a stock fendered '72 Lemans convertible. I run a Wheel Vintques 15x7 with a 4" backspace up front with a 255R60x15 tire. Out back I have 15x8 with a 4.5" backspace running a 275R60x15 tire. I have an issue with the rear tires rubbing when there is enough weight on the back of the car. I think my problem is the result of when the stock 10-bolt rear end was replaced with a Mosier 12-bolt and I don't think the Mosier is the stock length (width wise). However, Indyman Joe has a '72 Luxury Lemans, he has the same tires and wheels, and he has no clearance issues at all (he's now running a Ford 9" rear end).

So before you pony up for those plus size wheels, go get something like a Percy's WheelRite Wheel and Tire Fitment Tool from Summit Racing ($70.99) and measure all your wheel wells to be sure they will fit. The Percy tool will give you both back space as well as maximum tire size.

Edited March 11, 20206 yr by Frosty

Thanx for the tip on the fitment tool. Sounds like cheap insurance.