Last year when my dad and I started on my car (1984 GT hatchback), we did a 5-lug conversion and put four 17x8 Bullitts with worn out, mismatched 225/50R17's on them. Were starting working on it again and I'm wanting to run 275/40R17's in the rear with 245/45R17's in the front. I know the 275's are too big for he wheels, but are they dangerously so? If so, I'll run 245's on all four corners. I'll also need lowering springs if someone could suggest some that would lower it about 1.5"-2". Thanks.