I have a 71 riviera, and bought new wheels for it. I bought 18" wheels in the rear and 17's up front. I want to achieve a medium low profile look, but dont want it to be way to low. I want a wider tire in the back then up front. The front wheel is a 17x7 with a +6 offset, and a 4.5 backspacing The rear wheel is a 18x8 0 offset and 4.5 backspacing. I want wide wheels in the rear, to atleast fill out the wheel well. and I'd like to avoid any wheel rub up front. Tires i'm looking at are: 255x40x17 & 275x40x18 Will these work for what I'm wanting? Thanks in advance