Rear Ends

Well, sadly with the rear end, going cheap will come back big time to bit you in the ass. Unless you spend around $400 for a locker, you will get some POS. You can buy a used 3rd member with the gear ratio you want and just swap it. You can also use a SN95 rear end, but you will have to pay a shop to shorten it to it fits. Plus you will have to have the proper mounts welded on which means proper pinion angle. Cheap way in my mind and best is to look in the paper or on ebay for rebuilt 3rd member with the ratio you want and with LSD. As for what gears, well that depends. If you have a T-5 or some tranny with overdrive and want some more performance geared then get 4.11's. If you want a little of both, then 3.55's or 3.73's.

Why not just put a 3.55 trac-loc in the 8" you already have? You're not running enough power to break it, unless you get stupid,