i have a 84 z28 with a lg4 and a 5 speed. i was just wondering exactly what i would need to convert my stock rear end to a 3.73 posi. i have head differnt stuff about getting 28 spline axels, but what would happen if i didnt? and where can i buy these parts to make the switch? thanks guys.

 

You can buy a posi and gears for a 26 spline axle like you have.
Most people will try to talk you into the zexel torsen takeout from slp they are cheap priced but require 28 spline axles.
Jegs, summit, west coast differentials, randys ring and pinion have everything you need, I went with reider racing and was very happy, I got genuine GM gears and their (reider) install kit is top quality.
You need gears, posi unit, install kit at minimum, also good to get axle bearings and seals. Probably looking at $550 - $600 for the parts.

 

I think your better off getting a complete rear. I bought my 3.73/posi/disc brake rear for $300 and it only had 2k miles on it since it had been completely rebuilt with a new carrier and richmond gears. The carrier alone is worth almost that much. Do some shopping and be patient, deals come along every so often.

 

Powertrax performance locker or no-slip system. That would work great for you car since you don't need gears. To install either powertrax, you won't have to remove the gears or carrier.
www.powertrax.com