275's in the stock fenders?
 

I have some 17" momo sport wheels and some 275-40-17 tires sitting around, and I'd really like them to be on my FD. :D

I'm not sure what offset the momo's are - but I really doubt anything would rub on the inside... but will a 275 fit underneath the fenders? even in front?

Depending the wheel offset, they will fit. However, 275/40 is too tall up front and you'll eat through the fender liners and into your main electrical harness.