[highrisk]

Here is what I finally ended up with for my 1965 GTO. Wheels are American Racing Hopster Chrome 17" wheels. The front are 17x7 with 4.75" backspace and Kumho Solus TA71 215/55/17 tires. American Racing recommended 4.5"BS with these tires and wheels on this car and then I increased that by .25" for front disc brakes. Since my engine has a lot lot of aluminum I cut one full coil off of stock MOGG 5244 front coils (stock 4 speed with A/C springs).
The rear are 17x8 with 5.75"BS and Kumho Solus TA71 245/50/17 tires. American Racing recommended 5"BS with these wheels and tires on this car. I then increased that by 1/2" for a later model rearend (wider) and 1/4" for disc brakes. The rear coils are original MOGG for a 1965 GTO convertible (I believe they are 5237 but am not sure).
The shocks are KYB Gas-A-Just shocks and I am running the stock upper and lower A arms in the front with boxed lower arms in the rear. The front sway bar is 1 1/8" and I added a 7/8" rear sway bar and the frame reinforcement braces in the rear. The steering gear box was rebuilt with quick ratio gears out of an IROC-Z.
Dale