Scott, which trans-am car do you work for? We were at Nazareth all weekend for the Indy car race. I'm unsure at to what they use in the cars as far as diffs are concerned. I know most of them use lola trans. but as they turned a corner while being pushed, there didnt seem to be any chunking of the tires. Perhaps they unlock as power is taken off. Anyone know for sure? r.mair