Which Differential Should I Get?

im not sure what losi unit to get. i already have a set of 28 spline axles laying around and a 3:73 gear but need a differential.is there a certain series i need and dimensions?

I believe the best bargain around is the SLP Zexel Torsen posi unit, built specifically for 28 spline axles.

It was retailing for about $100 US, a bargain if you know anything about posis!

I bought my zexel for $85 when SLP had them on sale. I've had it in for a couple hundred miles so far and I'm extremely happy with it. It grabs well and is completely smooth and quiet around corners.