Will these fit and what will fit better on an A-Body

[Nemesis RR]

Will this package fit on a 1970 Pontiac Lemans? The wheel is the Foose Nitrous wheel. What backspacing and tire size would be better?

Rear 18x10 with 5.3 or 4.5 inch backspace 295/35/18 (26.18 diameter) or 295/45/18 (28.46 diameter) Nitto Tire

Front 18x8.5 with 4 or 4.5 inch backspace 245/40/18 25.59 diameter Nitto Tire

Nitto recommends a 9" wide wheel for a 265/275 tire. Should or could I try the 265 or 275 on a 8.5 wide rim for the front?

[Roadbuster]

The 18x8.5 with 4 bs and a 265 will probably not fit. You need more back spacing and some suspension mods to correct the positive camber gain to get that wheel to fit. Even the 4.5 bs will give you issues.

[ponchopwr70]

I fit a 17x9.5 with a nitto drag radial 315/35-17 on a 5.5 backspacing front and rear. Im actually going to try to fit a 11" or 12" wide rim in the back with a 335. I think I have enough room. Take plenty of measurments. My fronts right now are 17x8 4.75 bs 255/45-17

[Nemesis RR]

I fit a 17x9.5 with a nitto drag radial 315/35-17 on a 5.5 backspacing front and rear. Im actually going to try to fit a 11" or 12" wide rim in the back with a 335. I think I have enough room. Take plenty of measurments. My fronts right now are 17x8 4.75 bs 255/45-17

Is your front end lowered at all?

[ponchopwr70]

Yes a lot. I'm tucking my front tire, wheel well lip is about a half inch below the top of the tire. I'm also running aggressive allignment specs. 6 degrees caster -1 degree camber