I've got 4.88s in my 83. with 33s. and a detroit in the back, like it all just fine. but the 4.88s do lower your road speed a bit. I can still make 70, but not a lot more with out reving more than I like to keep it at. I had 4.10s and was happy to lose'um, I've got a 5spd in mine and that helps with the raod trips