It appears I need a new oil pump in my TH400. Anyone have a GM part # so I can try gmpartsdirect.com ? I found a Hughes on summit for 52$ so far. Mine is scorred pretty evenly top to bottom on the gear and case. There are no grooves but I assume it should be smooth. Also I am hearing that I can increase holding strength by taking out one big steel and clutch set and putting in some smaller ones as long as the over all length is the same in the end. Would this be a good idea on a tow rig were heat is more of an issue than slippage? Wondering if the thinner steel would heat up quicker than a thicker one? My rebuild kit did not come with bushings so I am also looking for a GM part # for those if anyone has them. If not I found plenty of sets on the net cheap.