I had spacers machined out of incaloy *sp by a buddy of mine to make up the difference. So this is a bolt on affair.
Yes, with these particular wheels the tires do stick outside the fenders slightly. However, it matches the rearend that I used, and I think it looks better than the S10 conversions that tuck the tire too far under the fender in my opinion. Don't flame me, it's just my opinion.
This is the only pic I can find right now. Understand that in this picture the wheels are turned slightly left.
