txs

I bought an nv5600 to replace the 5 speed in my truck, the guy I got it off of said the 5600 was grinding in one of the gears. It has the 1 3/8" input, tranny is part# p52108502AB. Pulled pto cover, everything looks and feels good, should I go ahead and slap it in or replace the synchros, I am wondering if some of the slick synthetics might help? I heard there are aftermarket sychros out there that have superior lining, but they won't fit early trannies.

txs

I know someone is making better than stock blocker rings? the rings with the lining. Anyone know who?