17" Wheel/Tire size question on 67 Camaro

[tz1238]

I have a 67 Camaro SS, stock suspension, with 15 x 7 , 4-1/4 backspacing to the outer edge of the rim, Rally wheels in the front with 225/60/15 and 15 x 8, 4-1/2 backspacing, Ralley's with 275/60/15 Drag Radials in the rear. Both have 0 offset.I took the front wheels off to measure them I noticed they are rubbing against the frame when I have an extreme turn. The rears are about 3/4" away from the wheel wells, but I noticed that they rub slightly on the well (maybe the tire is flexing on extreme conditions??). I would like to put on Cragars SS 17" wheels, again 17 x 7 in front and 17 x 8 in back.I would like to fill the wheel well with the biggest side wall tire possible without rubbing. I want to get rid of the Drag Radials as driving in the rain is terrible. I need suggestions please. I want to order wheels and tires from Newstalgia and like everyone else I don't want to make a $1,400.00 mistake. Thanks

[68Formula]

Most run 9.5 with 5.5 backspacing. I have 275/40 on my '68 and luckily it sits a little high in back because I suspect under full compresssion it would rub on the lip. This setup probably works better on the '69s, than '67/8s. I've noticed a slight rubbing on the inside due to hard cornering.

If I could do it over again, I'd of installed del-a-lum bushings in the leaf springs (to further eliminate side deflection) instead of poly and used 17x10 on 6" backspacing so there is no side-wall buldge.

On the front I have 17x8s and 5" backspacing with 245/45, but it will just barely touch the frame on full lock. 4.75" backspacing is probably optimum for that width or better yet, do a 17x8.5 with 5" backspacing if you can.

The place I ordered my wheels from only had 8s and 9.5s and backspacing of 1/2 increments. Other wheel manufacturers are allow more custom sizes. Don't know about Cragers.