1974 Firebird

[srh3trinity]

I have a 74 too and I am going with a similar fitment as SW's that Ty mentioned. I bought some used tires to get it rolling on and they are 275's going on a 9.5 wheel. Eventually, I am hoping to go up to a 295 although that is pushing the limits of a 9.5 wheel. Mine are 18's.
One thing to consider, I am not sure if the 70-73's have the seatbelt hump that the 74's do, and that may need some massaging to fit the widest tire possible.