rear differential

I have a 1997 chevy s10 with a 2.2 5speed base model and i was wondering if i could get some help im wanting to put a limited slip in my rear end so i can get better traction in bad weather or towing. How can i go about it. I do believe i have the 7.5 rear end.

Does anyone know the rear differential spline count on this pickups? I'm looking at putting in a Lock-Rite from powertrax Drop In Lockers from PowerTrax They have a "new" design out for the 28 spline, thats supposedly better at not "chunking" on turns. Anyone have experience with these and...