Mine went bad in the 80k range, but I think that was due driving it for a few hundred miles while the clutch bracket and cracked. AAAMCO said the syncro's were gone. Didn't really like AAAMCO, but I know they are all different.

Perfect world (and having more time) I would have gone with a rebuilt one from the guy that specializes in dual cases / toyota transmission (can't think of his name. Jay maybe, Marlin????). Could have pulled it off the truck myself, bought one from him, put it back on and even with shipping saved ALOT of money. Plus AAAMCO lost a bunch of the bolts and replaced them with odd sized ones.

Best of luck