75 Manta Rims on a GT

[azopelnut]

I was thinking about putting a set of restored stock 1975 rims on my GT but realized when I compared them to a rusty GT rim that the 1975 stock rims have 3/4" more back space then the stock GT rim.
Questions
1) Won't I be narrowing the width of my tire track by 1 1/2 inches therefore make handling worse?
2) With a 185 70 13 and stock GT suspension will I get any interference with the 75 rims?

[West Coast GT]

How does one tell the difference between Manta rims and GT rims?

[azopelnut]

GT rims have GT stamped on the inside and are about 4 1/8 back space

[kwilford]

Paul, the '75 rims are 13x5 1/2 versus the standard 13x5 GT rims, and I think the '75 offset is a bit bigger. My Ascona wheels are out in the snow on the driveway (along with the car) but IIRC, they're ET35 or 38 versus ET25 for the GT. So while the backspace is a bit larger, the wheel is wider, and hence the centre line is in about the same place. That shouldn't hurt the handling.

I haven't tried them on the GT, but I suspect that they will fit fine, especially with the 185/70x13 tires. Bigger 205/60x13 "might" rub at full lock, but I doubt it.

[hrcollinsjr]

Paul,

I installed the '75 wheels on my GT some years ago. On the front at full suspension drop the standard wheel weights contacted the upper A arm. I had them use stick on weights on the inside. If you have "grippy" tires and push your car the inside rear pinch welds rubbed the sidewalls. I beat the pinch welds flat and installed a rear anti-sway bar to cut down on body lean. The extra 1/2" makes a small improvement in handling even if it is all to the inside.

HTH,
Harold

[opelenvy]

I put a set of 75's with 185 70 13 tires on my GT with sport suspension. Front and rear sway bars. During normal driving conditions I had no problems. I didn't push the car while I had them mounted, so I am not sure there.

http://www.opelgt.com/photos//data/5..._75_wheels.jpg

[hrcollinsjr]

Originally Posted by opelenvy I put a set of 75's with 185 70 13 tires on my GT with sport suspension. Front and rear sway bars.

Similar setup except I didn't have the sport suspension. Beating the pinch weld flat in the rear wheel wells may have been unnecessary and the odds of getting air and the front wheel weights getting ripped off are????

Harold