They are way over built. The factory did a great job with the drivetrain, except for the 2.6 and it's VSS issue Good power for the weight. My eldest has one of mine and runs the piss out of it, after I ran the piss out of it. Strong motors. Axle swap is going to cost a pretty penny unless you find a really good deal on something already geared at 4.10 plus, preferably 4.56 or higher. factory gearing is a pretty steep 4.62, you will be hard pressed to find axles geared sufficiently at a reasonable price to beat what you have.

89 SWB, V-6 5SPD, OME Shocks, 16.5X37's, 2"BL, SR axle, Gen2 brakes, Lincoln w/Superwinch