Re: Posi units.
The Wavetrac is only available in 35 spline and sold exclusively through Moser. I think you're right about the Truetrac being available in 35 but I haven't heard a lot of good things about them in high power cars. I'll probably try one in my C20 because there isn't really any other option. Besides, the 14 bolt is so huge it would be easy to make a strong unit. I have Detroits in a couple of off road rigs and I would never use one in a street machine. Eventually I'll pull the Detroit out of the rear of my FJ40 in favor of an ARB air locker. I'll leave the Detroit in the front. Detroits are bullet proof but really miserable on the street. I much prefer the spool to the Detroit.
It's really what you're willing to put up with
69 Malibu Stock 307, Reverse Manual TH350, 4,500 Stall Edge Converter, 4.56 Spool 35 Spline 12 Bolt
76 C20 VortecPro 496 628HP 655 lb/ft TH400 Edge Converter, 4.10 14 bolt