wheels have been a dream of mine since
Larry Shinoda penned them back in 1997.
These wheels are very common on American classic cars (Ever been to Hot August Nights up in Reno? It looks like a TT2 Love Fest), but they just look sooo good, I couldn't pass on 'em despite their popularity. I bought the wheels from Corvette Repair in Mountain View, CA.
The difficulty in putting 275mm (10.8") wide tires on the rear of '68 and '69
Corvettes is due to these model year cars having un-flared rear fenders. 1970 and up have roughly 1" wider rear fenders, so you can fit a 10" tire without getting fancy.
I spent quite a lot of time researching, and wasn't able to find any reasonable answer on what was required to do this, so I grabbed a ruler and went to work to develop a solution myself.
I have made no attempt at working up a 275mm wide tire solution for the front end of the car. That almost certainly would require flared fenders and a custom offset wheel to avoid clearance problems. I kept the front wheels on the stock 4" backspacing and it all works as expected.
Fat front tires are prone to following ruts and the crown in the road, making the car squirrelly to drive on the street. The main place where a wider front tire makes a great difference is on the road or autocross course.
Important Safety Tips First:
This may or may not work on your car. Your car may be different than mine, try this at your own wallet's risk.
If you have a pair of Vette Brakes "Smart Struts" on the car, this recipe may not work as a major amount of the clearance at the top of the wheel arch is due to the camber change from the suspension travel. If you have the Smart Struts, you will have to increase the backspacing to around 5" or so, but then things get dicey at the lower shock mount. Some additional ruler work is required on Smart Strut equipped cars as a result.
The Recipe:
- Rears wheels: 17x9.5" with a 4.5" backspacing.
- Fronts wheels:17x8" with the stock 4" back spacing.
- I installed Firestone SZ-50 EP tires. I highly recommend them, but you have a lot of excellent choices for high performance rubber. The rear tires are 275/40ZR17 (10.8" wide) and the fronts are 245/45ZR17 (9.6" wide).
- A pair of Vette Brakes offset trailing arms.
- Finally a Guldstrand shortened rear spring.
You may or may not have to install new shocks to handle the much stiffer (and infinitely better handling) 40 profile tires and rear spring. I have Bilstien shocks with valving chosen by Dave Herlinger to also match the F41 front springs and swaybars and love them.
My only handling complaints currently are related to the frame which flexes like a wet noodle. I have a spreader bar from Eckler's coming which I hope will help eliminate some of the frame flexing up front, but the only real cure for Shark frame flexing is to install a 4 point roll bar.
