Not to hijack this thread but what is involved in putting an lsd into a 95 s10? I have a 95 short wheelbase regular cab with a stock 4.3. I really like the truck but I just can't drive it in the rain. Seems like an LSD and some better tires and maybe bigger wheels might help?
Typically, putting the truck on axle stands, taking the wheels off, unbolting the rear sway bar if applicable, unbolting the cover, putting truck in neutral so diff can be rotated so that the cross bolt and center clip can be removed, then pushing both axles in slightly, removing the c clips, and pulling the axles out, undoing the differential retaining caps, fussing around a bit with a small pry bar to work the differential loose (sometimes they're a bit stuck in the bearing seats), carefully removing the differential taking care to keep the left and right separate. In some cases there are multiple thin shims, in others there may be just a single thicker shim, important to keep them ordered to their respective side.
Unbolt ring gear, transfer it to your new differential, torque it up, press on new differential bearings (old ones cannot be re-used), and basically reverse the process to reinstall.
Its a pita to do under a truck on the floor, I've done it on the floor once, on the bench once, and I've paid a shop to do it once. If I ever do it again I'll just pay the shop again. The differential with ring gears aren't light and its easy to pinch a finger putting it back in, given the lubricated nature of the thing it is also easy to drop it on your foot by accident...
mentioned, the eaton trutrac is generally considered the best limited slip differential for open replacement as it is a helical gear design. The factory LSD, along with auburn, and eaton's "positrac" are all centrifugal clutch design. That being said, unless you're using a junkyard unit, wearing out clutches isn't an issue for most owners in the lifetime of their trucks, or their lifetime. I put over 100,000mi on my auburn with clutches and I checked it before I removed the rear, still locked at spec and never had issues.
The factory "G80" RPO code simply refers to having a limited slip. GM used the same RPO for a few vehicles. S10's came with Gov-Lock LDS's known more commonly as Gov-Bombs, very few junkyard units are functional and best avoided. The F Body camaro's used a different differential commonly referred to as a Zexel/Torsen (Zexel being the former company name prior to Torsen), these were far superior, and even used are generally good with few issues and are still readily available:
GM 10 Bolt 7.5" and 7.625" Torsen Posi Differential Carrier 28 Spline Used
Thats what is involved, but unless you're mechanically inclined with access to common shop tools etc, having a shop do the job is the way to go. This is a few difficulty steps above being able to do your own brakes kinda thing.
The change in pinion depth and backlash comes mostly from the ring gear thickness differences between ratios, but when re-using the same ring and pinion, usually the pinion depth and backlash doesn't need to be altered. If you're going to change ratios at the same time to say go to 3.73's or something, then yes you definitely need a shop as measuring backlash and pinion depth isn't for the inexperienced.