You're right, there isn't much to change. usually, unless you're remmoving and reinstalling input shaft gears, rebuilding a T350 is mostly cleaning and visual inspection. All i really did was totally disassemble the donor unit (input shaft, output shaft, shift forks, rails, gear selector, roller bearing, sealed case bearings), clean them, inspect the syncro rings and dog teeth for undue wear, inspect the gear surfaces for the same, inspect the shift fork bushings for damage, make sure everything spins freely, then just reassemble.