My 94 3500 4x4 has been upgraded to a 6spd, i pulled the pto cover off after hearing a noise in the transmission only to find teeth in the bottom. This truck is a heavy hauler with an 11foot utility body that is the service truck for my heavy equipment repair buisness and is used to alot of off road work. Parts for this trans are rare and expensive as well service information being scarce. I have half a thought and have heard of a 10spd swap before in tdr pages and am looking for that information too. I know a 10spd like the back of my hand and while the truck is down might as well go all the way.