what rear end should i get?

i have 91 mustang 5.0 conv. with cervinis ram air hood and kit, c&l mass air flo meter and inlet pipe, bbk shorty headers, bassani x pipe, and flowmaster cat back system..... i will get a 70mm tb with egr spacer later but i want to know why my rear end only burns out on one wheel when i power brake? i feel that i should probably switch to posi traction....am i loosing 1/4 mile time the way i have it right now because of this? if i switch it will it give me better performance? and what should i get a new differential or just some rear end rebuild kits? i need help!@ and by doing this what do u think my quarter mile time would be?

The ford counterpart of posi traction is Trac-Lok, I'm pretty sure you already have trac-lok, you just need to get the clutch pack in your rear end rebuilt... If both wheels are spinning as a pose to one wheel you will get more traction which should help your launch. Of course, you should wait for others opinions as well...

what he said =)

i askd sac-mustang about it and they sayd i should rebuild the rear end as well....thats with the clutch packs and new bearings, is it possible to find a new differential that just slips in as a direct bolt on?