Well, to my knowledge, the rear end is original, but the driveshaft isnt. It was swapped out with the tranny. As for what I plan to use the truck for...generally just cruising around town, with the occasional drive out onto the highway. So I would like it to be fairly comfortable doing higher speeds. I don't have a tach, so I don't know how high it's revving. But, I did drive it at about 120k an hour (60 miles) for 5 hours straight, and it was fine. The tires are 235/75R15. Red, when you said that gears are "spendy", did you mean expensive? Would it actually be cheaper to replace the trans? I didnt know there was such thing as a 4 speed manual with overdrive. I thought about putting in an automatic with overdrive, but have grown to love driving the standard. But honestly, as long as I can get it to do a good highway speed without too much strain on the engine, I'm happy:)