Get yourself a limited slip positraction carrier.
An 'Auburn' posi is a good one. A 'cone style' that gives good grip without too much trouble. Same with a disc type clutch pack. Only things you need to watch are (a) posi lube addative is required, and having your tire size (rollout) match is real important.
Stay away from 'locker' type units on the street. They are fine when they are in 'lockup' as long as you are going straight...But if you go around a corner and it is wet...they may not unlock and you may spin the bugger out... Or...You have to spin the tires to get the locker part to latch in. If you don't, then if you take off at, say, 3/4 throttle and get on it without spinning the tires...it will drive off of one wheel. Feels a bit squirrely then..dart one way on the gas, and the other way when you back out of it...
I had a Detroit locker (9") in my truck and replaced it with an Auburn posi.. Smooth as silk with the Auburn. Clunky and jerky with the locker...
Hope the info helps...
Jeff