Mike, I just went and checked for you, The firebird chassis is way to wide to fit. The olds chassis fits pretty good and wheelbase is pretty close. The pro sportsman (55 and 57 Chev) are almost made for it (you would need to cut off just bebind the wheel tubs on all of them) and those kits are still pretty easy to get hold of, that's the way I would go if it were me.