Backspacing for a C-4 suspension?

I am moving ahead on my C-4 suspension conversion on my 72 frame. I need to get the wheels before I can really start doing anything. I am looking at some Coddington wheels, the F-22's. I need 18 by 12 for the rear and 18 by 10 for the front. The first question is what backspacing? What is the stock backspacing for an 86 vette front and rear? If I needed more backspaacing, what is the max I could go? I want to try and tuck both ends in enough to fit the stock fenders if possible, if I have to I could add a subtle flair but thats only if I need to. According to Boyd's site, the available backspacing is between 4 and 8.25 for the front and rear. Even though this is the wrong year, this is the look I am after with my 72.

Mike

In general, C4's have 36-38mm offset (1984-87) and 56mm offset (1988-96).

Are front and rear the same offset?

wickd said:

Are front and rear the same offset?

Click to expand...

I have same size on all 4 corners....17x9.5 so yes....

but some C4s had different size wheels f/r especilly the ZR1's with the 11" rears....I dunno about offsets, sorry...

wickd said:

Are front and rear the same offset?

Click to expand...

84-87 are the same front and rear.

88-up are the same offset (56mm) but the fronts are ~ 8.5 wide and the rears are ~9.5 wide.

Not sure about the "specials" like Z51, Grand Sports and ZR1. I think some of them used 11 inch wheels in the rear

I have the C-4 Z-51 suspension under my 71. I'm not sure if you can squeeze that wide of wheels under stock fenders.I'm running 9.5s and 12s but have big flares. It could be done with smaller flares but, I'm not sure what the offsets would be yet.