I am trying to go from my C5 corvette magnesium rims that are 17 x 8.5 in the front and 18 x 9.5 in the back. I have tires for them and the car sits perfectly level, its a 67 camaro.

I want to put 17 x 8 in the front and 18 x 9.5 perferrably in the back but am afraid of hitting my quarter lip like I am now. I was going to have a mod done to my frame to keep my axle from traveling so far up and hitting the lip and at the same time act like traction bars to keep my leaf springs from winding up. Its a simple thing to do just wanted to see your guys input. I am actually looking at Coy's wheels now too but they only make a 9.5" wheel in 18" diameter with a 5.5 bs.

Will these fit?? Or should I look at something different? Also whats the largest i can stuff under her.