275/35-18 Front Fitment Question - Attn 72BB and GDart

I was autocrossing with a member yesterday and he had 18x10 Mustang wheels with 265/35/18's all the way around on his '67 Valiant. He utilizes Dr Diffs 11" discs up front. The only difference was that he was running an 8.8 differential out back. He also has a body guy that was able to pull his rear fenders out about 2" using a pneumatic cylinder. It looked really nice.