I want to install 3.42 gears with a posi unit. Are the gears and posi unit all I need? Or are there spider gears and the like that must be installed as well?

 

There is more than one way to do this.

1) Buy a 3-series posi carrier and a set of 3.42 gears and have them installed.

2) Buy a set of 3.42 gears for a 2-series carrier, have them installed, then put a PowerTrax conversion in.

3) Buy a complete rear with 3.42 gears and put it in your car. If it has posi, you're ready to go. If it doesn't, get a PowerTrax conversion and put it in.

#'s 1 & 2 will end up costing you about the same, as the PowerTrax and posi carrier cost about the same. The PowerTrax will click as you go around corners, so you have to decide whether if you can live with that. The big advantage of the PowerTrax is that it can be installed without any special tools, but since you want to change gear ratio as well, that probably isn't a factor for you. But, they are somewhat tougher than a clutch-type posi as well.

The spider gears you have now will not be in the picture for you when this project is complete.

 

of your going for cheap, i'd say go with the torsen from slp and a gm or richmond 3.42 gear.

 

Cheap is one thing, but how much power can that setup take? Same as a stock 92 Z28?

 

I'd go with the SLP posi and a set of gears. I just saw gears for sale for $50 shipped on camaross.com. That'll do it.