cheers for all the info guys, yeah it is a VK with borg warner 3.08 ratio at the moment. It is mainly for street driving but i still wanna be quick over the quarter. i was thinking bout 3.9 at first was looking at LSD but cost might keep me to single spinner. i wanna do the diff for under 1000 if i can. I'm pretty sure that 3.45 is about highest you can get for em from a VL but i dunno apparetnly skyline centres will fitt 3.89 so i dunno, how much they would cost to fit.