With the truck not in gear it will rev to its hearts content, put it in gear and when it gets around 2200-2500 rpm it seems to retard itself and quits pulling. I can get up to whatever speed I need without and slipage or what I would think would be transmission/tc problems.

Also if it were transmission related I would think i could get the RPMs up put it would be slipping, this isnt the case. It just seems to hit a brick wall right after 2000, takes off just the same from a dead stop though, then hits the barrier.

any ideas?