I'm not sure about the maximium size you can run, but I know that you have to take into account the amount of back spacing you can use. If you get the correct backspacing, you might be surprised of the sizes you can run.
I have a 69 SSRS. I purchased two new reproduction 15 x 10 rally rims with a 5 in. backspace or offset. The tires I had mounted on these rims were BF Goodrich P295/50/R15's. As beautiful a sight as these tires were, they rubbed in the rear quarters while the vehicle went over small bumps. My complete suspension is brand new so it was not due to any sagging. My suggestion would be to stick with something just a tad bit smaller than my combo. Good Luck !!
Thanks for the info, and I hate to sound stupid, but I am a bodyman not mechanic.Is backspacing putting spacers behind the wheel? If so I would rather have the wheel deeper in the wheelhouse, than outward.But If you could almost fit 15/10 WOW.
The backspacing is the measurment of the depth of the back of the wheel (the part that faces the brakes). It is measured by placing the wheel on the ground backside facing up and laying a straight edge across the top edge of the wheel and measure down to the mounting pad (the part that accually touchs the brake drum or rotor). I hope this helps, if you need any more information about measuring back spacing look in the Summit Racing Catalog on page 215. The catalog I'm referring to has the red '47 Studebaker Pick up on the cover. I hope this helps.
I too have a 69 Z28. I'm looking to get that road racer look. I've read ALL of the wheels forum and still have a few questions. Is anyone certain of the back spacing? 4" or 4.5" for the 15x8 Vette Rallyes? Will they fit on the front, and is the backspacing on the front the same? Assume new suspension. HELP!!!
The 4.5" offset was a Camaro standard while the 4" was for Corvette. Chevrolet did not offer a rim larger than 15"x7"x4" offset for Camaro, while Corvettes got the bigger 15"x8"x4" offset. If you find a used 15"x8" rally it is likely a 4" offset rim. Wheel Vintiques offers a catalog that outlines these differences.
paul69 - How much clearance do you have between the rim and the suspension components? I'm considering 15"x8"x5" offset for the rear but the clearance between the shocks and shock plates seems to be pretty tight.