widest tire-wheel combo for a C-3?

DJ Dep

DJ Dep

refugee from the other place
Joined
Mar 23, 2008
Messages
718
Location
Silver City, NM
I was looking in Jegs and Summit and they show a 15X10 inch factory-style rally wheel for the Vette. Will this fit on a 1972 and what size (width) tire could I install on it? The Vette parts books warn about installing an offset something-or-other to use wider tires. I'm not looking to install gigantic wrinkel walls, just would like something about as wide as the 10 inch wheel.
 
I have '89 vette wheels on my '72, with VBP 2.5" wheel adapters on all 4 corners...rims are 17x9.5" and so I pretty well kept the same wheel/tire centerline....stock was 8" rims so 3/4 inch on either side....rocket science....

but that meant to remove the ebrake cable mount and most guys put it up top, I moved mine to behind the rotor....been there since '95 or so....not that the ebrake ever was worth a shit anyway....:hissyfit:

trick is, I have been running 275/50/17 in the rear soon as I found that size by Nitto....unfortunately they have dropped the size from the lineup....so I suppose 255/50/17 same as front will have to do....

how you work it for your rim diameter is a mechanical/measure, I can tell you it's possible....but keep in mind, my '72 has the flares of a later shark, not the early shark, P/O did that work...not me...
 
Gene: I can't (read won't) use wheel adapters. I just don't trust them. The wheels I am looking at are identical to the factory 8 inch Rally wheels except they are 10 inches wide. Same offset and everything. I think I may just end up using the factory wheels with 8 inch slicks, though. I don't want to order wheels and tires and then have them not fit or have to do a ton of fiddling around to make them fit.
 
DJ Dep said:
Gene: I can't (read won't) use wheel adapters. I just don't trust them. The wheels I am looking at are identical to the factory 8 inch Rally wheels except they are 10 inches wide. Same offset and everything. I think I may just end up using the factory wheels with 8 inch slicks, though. I don't want to order wheels and tires and then have them not fit or have to do a ton of fiddling around to make them fit.
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Dep, methinks you are thinking of the cheep old shit spacers we see in the parts houses from some junk company, these adaptors have been on the car since '95 and are in fact stronger than the wheels themselves, made from billet aluminum, if memory is correct....it takes ten lug nutz to get to the rotors, and the wheel studs are interleaved and take standard length studs/nutz....but at any rate you seem to have your solution in hand, but I used C4 wheels mainly because of price....

:hi:
 
Dep...I looked at BF Goodrock offerring for 10 in to get an idea of the section width...only size is 295 50 15

The section width...sidewall to sidewall is 12.2 inches which is a whole 2 inches wider that my 255/60 15's. The extra inch on the inside would most likely hit the stock trailing arms and bracket.
 
SmokinBBC said:
Dep...I looked at BF Goodrock offerring for 10 in to get an idea of the section width...only size is 295 50 15

The section width...sidewall to sidewall is 12.2 inches which is a whole 2 inches wider that my 255/60 15's. The extra inch on the inside would most likely hit the stock trailing arms and bracket.
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Thanks Paul. Saves me some headaches with that info. Guess it will be 8 inch slicks on the factory 8 inch wheels. I need to take off the rear wheels and then toss the tires. They went flat and the sidewalls cracked and split. Then I need to take the wheels in for sandblasting. They are rusty inside and prevented the bead from taking a good seal. :)
 
I wasn't really worried about fender clearance, but I was a bit concerned about the T/A and e-brake cable. Ended up with 17x9.5 with 4" backspace cleared everything. Wrapped them with 295/40 tires- 11.5 wide tread. Goodyear Eagles of some flavor. Turns out I had enough room for another 4" wide of a tire to fill the flares.
 
Sorry to resurrect this thread, but I have one more question. Is the factory wheel for a 1972 a 15 X 8 with 4 inch offset? I think it is, but want to be sure before I order some.
 
DJ Dep said:
Sorry to resurrect this thread, but I have one more question. Is the factory wheel for a 1972 a 15 X 8 with 4 inch offset? I think it is, but want to be sure before I order some.
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Kid Vette said:
DJ Dep said:
Sorry to resurrect this thread, but I have one more question. Is the factory wheel for a 1972 a 15 X 8 with 4 inch offset? I think it is, but want to be sure before I order some.
Click to expand...

I think its 4" backspace and -12mm offset.
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Here is where things got a little wacky for me, IF you look at a tire rack site for instance, you find a wheel profile and so the measure the wheel width between the steel/aluminum the bead seals on....INNER measure...they do the same for offsets to the mounting center face on inside....just to be consistent, I suppose, from a engineering standpoint....

BUT when we measure, All I have ever done is take a good straight edge to the FLAT side of the tire bead flange, not the lip edge, and measure to the mounting flange, add what is needed for subtract ~1/4 inch for material in the flange, and that is what a rim maker would use....
1/4 inch was my best guess, being lazy.....I was calculating what wheel adapter would allow snug clearance and same overall tire centerline mainly concerned for the rear with stock C3 configuration....the fronts wound up being more problematical, and so I returned the 2.25" adapters for the 2.5" adapters, making everything happy up front....that has been the case with stock steering and the rack install...

BTW, my stock steel rims with rings/center chrome had a 3.5" offset to the outer flange from mount surface....factory measure be 3.25"

This is on my '72 vette, I can't say for later shark mag wheels....

:D
 
Ordered the wheels today from Summit. Thanks to everyone for all the help. Next is a pair of Cooper Cobra GT P245/60R15 tires. :bounce:
 
Got my wheels today from Summit. WOW!!! They are actually the same color as the old ones. However, they are gonna get a paint job. There is a label on them from Wheel Vintiques stating the finish on the wheels is NOT rust resistant. So I'll get a couple of cans of Rustoleum silver from Ace Hardware and give them a coating.
 
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