I have American racing wheels on my 75 that mount w/o any spacers. If you go to their website I believe you can do a search for your vehicle and it will tell you which models will fit. The problem with c3 vettes is the clearance between the wheel and brake caliper. I would stay away from wheels that need spacers if at all possible. If you do use them keep your lug nuts tightened properly.
I have older American Racing rims on my '81. I agree with Roy, stay away from spacers if at all possible. I ended up having to grind off about a 1/4" off the end of the caliper housings to clear the rims. Maybe a bit risky but there was plenty of material. Never have had a problem.
I agree, stay away from spacers if at all possible. If you do have to go with spacers, use a quality set such as Vette Brakes and Products. Not to many aftermarket wheels fit the C3 without spacers. American Racing Torque Thrust is the most popular. I just got a new Jegs catalog which shows Cragar now making 17" Torque Thrust style wheels with a better selection of offsets. I think they even have a 4-1/2" offset which should fit without spacers. They are also about $50.00 per rim cheaper than AR. Check it out.
Aw Jack, You say the nicest things.....Gee, I don't know where that came from.
Anyway, I am using American Racing Torque Thrust II's with Goodyear Eagle HP-Ultra-Plus tires. 16x8 + 255/50-16's. After much research, I found that the American Racing wheels fit best and had the look I wanted. If I remember correctly, the Cragar Wheels are not polished aluminum but chrome plated steel. That was a no-brainer for me. I used the Crager's on other cars I had but wanted the polished aluminum for my '70.
The problem with fitting and our Vette's is the calipers, and whether a certain wheel will fit depends on the backspacing and the design of the back of the wheel. I'd stay with 4 inch backspacing, any larger with 16inch wheels and you'll run the wheel into the rear spring and parking brake cable bracket. Believe me I tried a set of Hailbrand 5-spoke's with 4.5 in backspacing.
Now if you go up to 17 inch wheels, I believe you can increase the backspacing to 4.5 inches.
I agree with the others, avoid using spacers to clear the calipers.
I was told about 6 months ago that Crager wheels was going out of business. This was by a tire/wheels store manager who even called his supplier to confirm this. I don't know if it's true or not and as Crager has been around since the beginning of custom wheels I would think not. Just to be sure I went with AR wheels so not to end up with something I couldn't replace just 1 wheel if it was damaged. Has anyone else heard this rumor ?
As for the wheels I used, they fit w/o spacers and look great. I don't remember the model off hand but they are current a current model.