sarjag97

Hi Everyone. I'm new to the the forum and appreciate all the great info that gets exchanged. I have a 71 roadster that I am rebuilding from the ground up and want to use 18"x8.5 C6 wheels all around. I have done a test fit using a friend's wheel and a homemade wooden spacer and they look like they will work... if I use a 3" spacer. I have found only one website offering such a wide spacer but have not found anyone that has used them, for better or worse. I am wondering about durability and whether these will cause early wheel bearing failure. Any input will be appreciated. Thanks and happy New Year.

Steve

grassyflats

http://forums.corvetteforum.com/c4-g...and-video.html

grassyflats

http://www.motorsport-tech.com/wheel_adapters.html

blckslvr79

I ordered my adapters/spacers from JR at Motorsport Tech also.

Very easy to deal with, although I had to wait a month because their machinery broke down.

The adapters are very nice quality and I opted up for both car and wheel hub centric. Cost will depend on your thickness needed, I paid $350 shipped for a set of 4 but I needed 3.75" thick custom adapters (3.50" would have worked) for the rear using the 19x10 wheels and 2.75" for the front 18x8.5 wheels.

If you want to save money, adapters from 3" down (non wheel centric) can be found all over Ebay for under $200.

3" adapters will be too thick for you. I used 2.75" on the front for the 18x8.5 wheels and it came out perfect. On the back you should need the same if you are using the same 8.5" wheel.

sarjag97

blckslvr79: The wheels on your 79 are the same type I plan to use (unless something else catches my eye). They look great on your car. 2.75" spacers should work. With a 3" spacer (4" backspace) it looks like I have a good 1/2" to spare so I may even be okay with 2.5" spacers. No concerns about early wheel bearing failure? I was trying to attached pictures of my test fit but can't figure out how.

I'll check the other websites for spacers as well. Thanks.

blckslvr79

2.5 might work, It will put you very close to the inner wheel well in the rear. I did not like the look of the 2.5 on the front as the tire sat inward too far and would rub the frame on full turn with 255 tires. The 2.75 gives me some room if I should decide to up my tire sizes in the front.

I'd go with 2.75 on these, but 2.5 would probably work for you too.
3" would push your tires to far outward and probably cause the tires to hit the fender lip under suspension compression.

The above adapter builder was the best I could find. I'd buy from him again. His adapters, like I said, are both "car AND wheel" hub centric, while the others on Ebay are only hub centric to your car, so the wheels are relying entirely on the lug bolts. I forget how many thousands of pounds of shear side load pressure it is on the lugs just hitting a pot hole. IMO, wheel hub centric adapters are important.

As for wearing out bearings....Opinions go both ways. Naysayers complain about the extra force, but there are numerous people running the adapters for decades on this site with no issues and they are hard on their cars. I'm not worried about it. Besides, how many miles do we actually put on these?

baxsom

if you like those wheels shown above you could always get the SLP wheels. They come in chrome and hyperblack and they fit the C3 without spacers.

sarjag97

What do you mean "SLP wheels"?

blckslvr79

I think he's talking about these:
http://www.ecklers.com/corvette-zr1-...1968-1982.html

Direct fit, but not exactly the same.

sarjag97

I know about the wheels at Ecklers, but they are only 17 x 8", the last time I looked.

sarjag97

blckslvr79: By the way, are the hub bore on your C3 and the wheel bore on the C6 wheels the same?

blckslvr79

I never measured the two so I couldn't tell you if they are the "same".

As for the adapter fitment....
I'd say within a thousandth or so. The C6 wheels fit the adapter snug like a Lego, but the Adapter to the car fit has just a bit of looseness. Snug, but not as tight.

I didn't check the tolarances so I'm not sure if it's in the machining or if the car hub is a hair smaller.

sarjag97

Thanks for the info everyone. The bottom line is that if I find a good deal on a set of 18x8.5 C6 wheels, I will get a set of adapters. Otherwise I may wait to see if some vendor comes out with a set of 18x8 or 18x8.5 wheels made to fit a C3. This forum is GREAT!!!!

Steve

blckslvr79

Good luck with it! One thing is for sure, our sexy C3's have the ability to make even the ugliest wheels look good. What ever you choose will look good.