18 inch tires for 71 gto

[novaracer_2000]

I am currently building my 71 gto convert.I am getting close to assembling the frame and want to order the wheels.I leaning towards coy c5s.It looks like the rims to use are 18x8 front and 18x9.5 rear wth 5.5 backspace.What is the biggest tire I can fit in the back?Anyone with a gto with 18s have any pics?I don't want to run a super tall or a super short tire.I was thinking a 40 or 45 series.Thanks.

[PT Goat]

A 255 would be no problem, and a 275 should work. Any wider than that and you'll probably need to do some permanent mods.

[novaracer_2000]

I don't mind doing mods to the inner wheel tubs if i have to to run a bigger tire.I know the 71 gto they did on horsepower tv they used a 275.I was hoping to go bigger.

[Blown353]

68-72 Chevy A-bodies have no problem handling 9.5" wide wheels up front and 11" wide out back without mods... I'm not sure about Pontiac fitment though or how their wheelwell shapes & widths are. I would guess they are very similar to a Chevy of the same year but hopefully someone can chime in.

[ponchopwr70]

I have 17x8 and 17x9.5 with 255/285 combo. These are on a 70 lemans. I can go a little wider on mine. I think a 315 will fit. Pics of my car are in my sig.

[novaracer_2000]

thanks

[andrewb70]

Im running 295/45-18s in the back and 255/45-18s in the rear. I am thinking about running 305/35-18s and 275/35-18s.

Andrew

[novaracer_2000]

I like the look of yours.What size rims and did you do anything in the rear to fit them?I had a 295/50/15 on the car before I took it apart and they fit good.

[andrewb70]

I like the look of yours.What size rims and did you do anything in the rear to fit them?I had a 295/50/15 on the car before I took it apart and they fit good.

The rears are 10.5 inches wide with 6.5 inches of backspacing. The fronts are 8 inches wide with 4.5 inches of backspacing. I'm going to have the fronts widened to 9.5 with 5.5 inches of backspacing to run the 275/35 tire. The rear lip is slightly rolled but its not required.

Andrew

[novaracer_2000]

Allright thanks.I think I am going to run the 255/45 and 295/45s

[DriverzInc]

You should think about the Foose wheels we have on sale, we can get those tire sizes for you too:

https://www.pro-touring.com/forum/sh...ad.php?t=39957

[novaracer_2000]

So I ordered 255/45/18 and 295/45/18 nittos and 18x8 and 18x9.5 coy grey center c5s.Can't wait to get them!Even though it sucks that my car won't be on the road for at least a year,maybe they will fit on my nova.

[novaracer_2000]

I got the tires today,wheels should be here next week.Threw one under the back of the body,looks pretty cool.

[novaracer_2000]

got my coys today.Had great customer service and fast shipping.

[64Chevelle]

How much did that combo set you back?

[novaracer_2000]

I bought the wheels direct from coy and they were 900 plus 100 shipping including lug nuts and valve stems.The tires i bought off ebay from discounttiresdirect and they were 770 shipped.

[GHOSTDANCER]

any updates on this cool build ?