95 Chevy K2500 5.7 4l80e trannie problems

[samtg555]

Hi, I've been having some problems with my transmission, the 4l80e. Our friend took the engine out, then we rebuilt it about a year and a half later. Which means, it sat for a little more than a year not installed in the truck. Then recently, my dad and I took it to our house in Connecticut from Vermont on a trailer to work out some bugs with the engine. Runs great now, but doesn't move well. When I put it in drive, and give it gas it doesn't seem to have any torque. It seems to be in a higher gear, or it might be slipping, I don't really know. Nothing changes when i manually select the gear, i.e. 1st, 2nd, 3rd. However, when put in reverse, it has all the power in the world, which I would think would rule out the toque converter. The wiring to the transmission is undamaged, as we checked the wires with an ohm meter. We took off the trans pan, replaced the filter, tested all the solenoids, put in brand new trannie fluid, got a new PCM and a new TPS, all to no avail. So we jacked up the back end. When we put it in drive, it seemed to start in a higher gear, like before. However, manually selecting the gears worked pretty well. Also, there were no computer codes, and the transmission worked perfectly prior to engine removal. We need this truck up and running in about 4 weeks, any and all help is greatly appreciated. Thanks in advance!