Currently i have a open 10 bolt 373. My tire...spins a good amount when i get on it. I want to install a posi unit. Which will probably eliminate wheel spin. I wana have a little fun without having to power brake it all the time. Should i stay with 373s or go to a lower gear? I have a 28" tire.

3.73 is a great performance gear, but a bit much for extended highway use even with a 28" tire. But for acceleration is very good.

Does anyone know if they make a PowerTrax for 10 bolts?

I think the Lock Right Locker (original locker from Power Trax)is the way to go for strength and durability. May be a little noiser than the No Slip model, but stronger, the No Slip is for more daily driven vehicles. They have them for GM 10 bolts. Do a search for the Lock Right on this sight you should find plenty of info.