Stephen, I noticed on your site your IROC has 15 X 10 wheels with 28 X 9 ET Drags, My question is what is the offset of the wheels and what (if anything) did you have to do the inner wheelwells to get them to fit w/o scrubbing. I have 15 X 8.5 Convo Pros on my Z28 now, but they have only a 3" B/S which means they stick out about 1 1/2 or so past the outer lip of the rear quarter causing them to scrub occasionally and restricting the ride height of the car. Your wheels seem to be pretty tucked under the quarter, and since I have a new set 28 X 10.5 ET Drags, I want to go ahead and mount them on new rims with a more desirable offset than what I have. Thanks in advance.

 

I thought it was somewhere on my site but I guess it isn't.

The 15 x 10 rims have 5.5" backspacing. Regardless of rim size, the 5.5" backspace is the most you can tuck the wheels under the fenders when you have rear disk brakes. The rim will be about 1/2" from the park brake cable bracket on the caliper. There is plenty of room inside the fenders for my tires.

I'm probably going to leave the 28 x 9 tires on for now. I "know" I need wider tires and "think" I'm going to need taller tires with the 4.56 gears this year. It'll just depend on my shift point. Last fall with 4.10 gears I was shifting at 6500 and crossing the finish line just as the shift light was coming on. I want to push the shift point up to 6800. The 4.56 gears may make the car run out of rpm before the finish line. If it does then I'm going with a 29 or 29.5 x 11.5. The 11.5 should fit however a bit of hammering to the inner fenders will probably have to be done as well as rolling the fender lips.

I have some identical rims with 3.5" backspacing for when I finally cut up the rear floor and tub the car. (eventually some year)

I finally got my windshield changed. Lexan wasn't available so I went with Lucite instead (plexiglass, which is still legal for drag racing). It looks real good and cut another 20 pounds off the car. As soon as I figure out the best way to mount the door windows, I'll change them too and get rid of all the window regulator hardware from inside the doors.

I'm hoping the car, race ready, will be close to, if not below 3000 pounds this year.

 

I have the 15 x 10 rims on my car and i was able to et the car down but it needs a lot of hammering to clear everything good.

Im considering getting the grinder out and sectioning the ineer well. Cut it and hammer it back to clear and then lay a new piece in. Weld and undercoat. Good as stock.

 

To fit anything remotely big on our cars inner fender "massaging" must be done.

15X10 pro stars here with 7.5 inch backspacing. I run with a 28X12.5 ET street. No rub problems...I am going to try to put my buddies 29.5X10.5 ET Drags off his 95 Z-28 (non tubbed) on in the next few weeks. THAT is a good looking slick all crammed up under the fender.

Oh yeah, I did this by running a 4th gen 12 bolt on my car...the axle tubes are longer than the 3rd gens.

 

So take off the extra 2" for the 4th gen tube and the 7.5" backspace rims will be 5.5" backspace with the same results for the tires.

Let us know how the 29.5 x 10.5 tires fit. MT says that those tires are really 29.9" tall.

ET street and ET drag tires are measured differently. A drag tire is measured across the tread width. A DOT tire like the ET street is measured across the tire section.

 

Boy would I love to fit 5.5 BS rims on my 82 drum rear bird. I tried 5in and they rubbed the e-brake cable and on any slight turn the tires rubbed the inner wheel well, A hammer could have fixed that though. I opted for 4.5in.
Later
John

 

Yes, the actual measurement of the "29.5" is actually very close to 30 inches
I realize the difference in measurement of Drags and Streets...a 12.5 ET street is the same width as a 10.5 ET drag.

 

I've got a set of 28x10.5 M/T Drag tires mounted on a set of 8" rims with 4" back spacing and they only rubbed ever so slightly on the outer fender lip on uneven deep dips, but it didn't take much to fix that!