Stopped by my friends body shop this morning. He is finishing up his 3 year restoration of his numbers matching '68 Corvette 427, 4 speed, factory A/C. The car is absolutely amazing.

Anyway's, he has a set of factory 15" aluminum Vette wheels, not sure of the year they came off of. He's going to bring one of them to the shop so I can look at them. He also has a bunch of 15x8 Corvette Rally wheels with the caps and rings. He said he'd hook me up the 15x8 Rally Wheels pretty cheap. I was going to go from my 14" wheels to 15" wheel when I got the money. Depending on how much he wants for the wheels, might just do it now.

I told him I'd like to run 15x7 wheels in the front and 15x8 wheels in the rear. He thinks he has at least a pair of 15x7 wheels.

So I have a few questions.

Front- If I go with 15x7 wheels, I'd like to go with 235/60-15 tires (26.1" tall, 9.5" sect. width measured on a 15x7 wheel) how much back spacing do I need? Also, will the 15x8 wheels fit on the front if he doesn't have a pair of 15x7 wheels? What back spacing would I need if they'll fit?

Rear- If I go with 15x8 wheels, I'd like to go with 255/60-15 tires (27.1" tall, 10.2" sect. width measured on a 15x7.5 wheel) how much back spacing do I need?

I want both the front and rear tires and wheels to look like they're supposed to be on the car, meaning I want them in the wheel wells like they should be. I want to know the back spacing I need so I can measure them before I buy them. My 2 1/2" Flowmaster exhaust system with the single transverse muffler does come into the rear of the wheel wells a little bit. I don't think they'll be an issue though.

I'll take all the advice I can get so please chime in.

Thanks, NYH1!

 

You can use 15" wheels all around easily. The 15x8 will be too wide in front with any tire that fits that width properly. Best stay with 15x7" fropnt. To determine what back spacing you need you can bolt a stick or ruler across the face of your front or rear hub, then measure from center of the hub out 1/2 the diameter of your tires. At that point you can tape a dowell to the stick and check for clearance. In front you'll need to turn the wheels lock to lock and measure for intefereence. Once you see how much to move the dowell to clear, then you can figure your backspacing by subtracting 1/2" to give a bit of extra clearance. Repeat for the rear by just attaching to brake drum face.
You should have your car supported under the control arm or axle to get actual ride height while taking measurements. Also, the engine will need to be in to determine the actual stance.

 

I have the 15x7 all around and run the tires you mention above. I have the stock early z28 wheels. I have had no problem with clearances or rubbing. My backspacing is 4.25 inches.

 

1971BB427, thanks for the info.

I found THIS on another site. 15 inch Z28 wheels (5 spoke mag type) had a .300" offset and 4.250" back spacing. The tire size was GR70-15. Which as far as I can tell was 27.5" tall with a section width of 8.5".

So I should be ok with 15x7 wheels with 4.250" back spacing with 235/60-15's on the front. I know guys that have ran them on the factory Z28 5 spoke mag wheels.

I'm pretty sure I know a guy that ran 255/60-15 on the same Z28 wheels. If I go with a 15x8 wheel I might need 4.500" back spacing.

I'll have to look into it a little more.

 

kyphur, thanks for the info!

 

No problem... thought my post became invisible.

Running 235/60/15's on the front and 255/60/15's on the rear with no problems whatsoever.



You can also do a search on summit's website for the F80 style coding and it will give you a height, sidewall and treadwidth in the description if I remember correctly.

 

Below is a pic of my old 79 Vette, that's what the 15" aluminum wheels look like. Even if the 8'' did fit up front, I don't think they would look very good on a Camaro.

 

I just talked to the guy I bought my Camaro from last year. He is going to trade me for my 14x7 Nova Style Rally Wheels for a set of 15x7 Z28 Mag Wheels at not cost!

I'll probably run 235/60-15 on the front and 255/60-15 on the rear. The wheels need to be sand blasted and painted. But that's no big deal I have all the stuff to do it. The Z28 Mag Wheels are the wheels I really wanted anyway's!

 

Sounds good man. I know MT makes some tires that are 275's that will fit a 7 inch rim if you want to go that big.

 

I'm not sure the 4.5" backspacing will work, especially with a larger wheel/tire combo back there. The bigger the tire, the less backspacing you want. So if you go larger, then you should go smaller on the backspacing.
I'm running 10" rims out back, and I'm at 3.5" backspacing, and my tires occasionally rub the exhaust pipe when cornering agressively.