My dad has a 5.9L 2007 with the manual trans. The engine was ran low on oil a few too many times and it needed to be replaced. He got a good deal on a rolled 2004 automatic truck and we used it for an engine swap. I have read many many forum posts about this swap, so it has not been a problem with electronics or wiring, etc.
The '04 engine is already in place and the truck runs great. The problem is the transmission, it won't shift when running (it does shift with the truck off). The truck was completely running and driving when the engine with blowby was removed. When dropping in the '04 engine it also got a new flywheel, clutch, cylinders, etc. Basically everything between the engine and trans is new. The guys have tried two sets of new cylinders, 2 new Napa clutches, and a new OEM clutch. Everything now is new OEM from Dodge.
Does anyone know what could be causing this transmission problem? Are there differences at the back of the engine between the '03-'04 and the '07 that could be messing with us? Has anyone done a NV5600 to G56 swap (reverse of normal procedure I know) and ran into problems? Thanks in advance.