I am interested in buying up a set of 2005-2006 gt rims for a c3 corvette because they are being sold so cheap.It would be great if someone could tell me the bolt hole spacing and backspacing of these rims.

 

I don't thiink that would be a good idea. They are not nearly as wide as what is currently on your C6 even if the back spacing and bolts do match. I think you would loose alot serious rubber that you need. You may want to go onto a wheel manufacturer web site and see if they have that information to be sure.

 

I own a c3 and they are about the same size.

 

Ford and Chrysler models use 4.5" bolt circle but I never heard of a GM model that did. Simply check a few aftermarket sites for wheels on that year Corvette and you'll see the bolt circle. I'd be shocked if it was 4.5".

 

I misread your message, not the first time. I'll be picking up a C3 towards the end of the month from my uncle. We just had it appraised and we need to come to an agreement on the price first.

 

+1 Chevy uses a 5x4.75" bolt circle in every car I've seen.

 

so the answer to my question is the 2005-2006 mustangs have a 4.5 bolt circle? what about the back spacing, if need be I can machine wheel adaptors.

 

uggh..don't run wheel spacers, they're unsafe and change the handling characteristics of the car since it changes the center of gravity for steering

 

Ford rims won't even bolt to Chev, so spacers are moot anyway. Put the idea of Mustang rims on a Corvette out of your mind as fast as you can. There are hundreds of wheel choices for the C3;

 

In the case of C3 suspension, the use of spacers on our wheels may not have such a negative impact.

2005-06 Mustang GT wheels (18x8.5") have +50mm offset. The use of spacers would bring the wheel OUT further, and thus bring the offset number down. Ex: 1/4" spacer would bring it down to approx. +44mm offset. But a spacer safe enough for use with studs is usually 1/2" or more. That would bring them down to +39mm offset. Since the C3s are a bit older, they may have come from the factory with offsets in this range.

Side note: backspacing is not the significant measurement w/respect to suspension geometry...and that's what Derf00 was concerned with. Backspacing is derivative of offset (for a given wheel width), but is only relevant for clearance purposes. Offset measures the distance from the wheel hub mounting surface to the centerline of the wheel--this distance has a great impact on how the supension works within its design geometry, since it should've come from the factory with an optimized offset planned in the design. Keep the offset the same, move to wider wheel, and you have a new backspacing--but who cares (assuming you clear other suspension components). For handling, you want to keep offset close to stock (unless you know that the original design is flawed), you don't have to worry about backspacing unless you worry about interference.

Best,
-j