Back space

[machota154]

On a 1978 Trans Am, with 17's on the front, is 6.5 to much back space ?? I know the most used is 17's with 5.5 back space. Thanks for your help.

[machota154]

No one ????

[aronhk_md]

I believe you may find that is too much backspacing.

[MrQuick]

On 17's you most likely run into your sterring arms.

[Biodds]

Why don't you mount a wheel that is as close to what you want on the car and set the front tires on 4-5" of wood 2x6's or 2x8's. Then turn the wheel as far as it will go and climb under and measure. Look at the tire to swaybar clearance and the wheel to tie rod end clearance and A arm clearance on the back side. Then set the frame on jack stands and let the wheel droop down to the bump stops and check the clearance to the upper A arm. My guess is 6.5" may just fit depending on how wide of a tire you use. I run a Kumho XS 295/35-17 that is short enough to clear the fenders at full lock. I run a 17x10.5" CCW wheel on my '70 GS front end with 6 1/4" BS and the tire rubs the hollow Hotchkis swaybar because they didn't bend it very well but the 1 1/4 front bar I did have on the car from T/A like yours clears just fine. Be advised that the Kumho XS is a 180 treadwear tire and will put you in the Outlaw class at the PT events. If I had to buy new wheels today I think I would order 18's because there is more tire selection and also they give you more A arm and brake clearance.

[Randy67]

17" wheels with 5" backspace are real close to the tie rod end, 5.5" bs would probably be a safe maximum. I think the 6.5 would be close to hitting the upper ball joint as well and would hit the tie rod before the wheel seated.

[64impala]

On a 1978 Trans Am, with 17's on the front, is 6.5 to much back space ?? I know the most used is 17's with 5.5 back space. Thanks for your help.

Just spend the 65 dollars and buy the Wheel Rite fitment tool from Summit or Jegs. Takes all the guess work out. People here spend thousands on wheels/tires and wants everyones input as to what fits ....? Get the tool and simplify the process. There are to many variables getting input from others on the forum as to " what works for them" I bought the tool and I NAILED my setup on my 64 impala. Yes there are companies that can take the guess work out for you but its a great learning experience. My 2 cents. Hopes this helps and good luck

[PTS]

When in doubt get the tape measure out... Call us at 1-855-353-7883 and we will walk you thru the steps.

Regards,

Perry
PTS