So I have a problem...

[mcgoo26]

So, I am fairly new to C-10s, TH350s and everything, but everything is straight forward...or so it seems. So here is my issue: This last weekend I dropped the transmission to change out the torque converter. Reason being, when driving the truck, the transmission doesn't seem to want to shift at all when in drive. The engine will be at high RPMs, but takes forever to shift. After it is up to 30 mph or so, everything seems fine. So a co-worker who use to work in a garage suggested changing the torque converter. Basically going from least involved and expensive to more involved and expensive. So back to my issue. Over the weekend I swapped out the torque converter and even the modulator. I primed the new converter before install. It took about four quarts of fluid. I checked the transmission fluid level while at idle and it was just above the add line. I pulled it out of the driveway with no issues and took it for a test drive. A little better on the shifting, but not quite. So I parked it for the night in the driveway. Today I decided to try adjusting the modulator. I turned it clockwise about a turn or so and went about a half mile down the road for gas. The truck seemed to function better and actually responded. So I pulled into the drive way (which has an incline) to make about a half turn clockwise adjustment on the modulator. I make the adjustment and start it up for another test drive. Then the problem occurs. I have no reverse or neutral. When I put the truck in reverse, it lunged forward when pressing the gas. I put it in neutral, lunges then stops as if in park. I adjusted the linkage on the trans and on the column. Same result. I am at a lost on what may be the issue. I even backed the modulator off two turns to see (but from what I know, that doesn't affect this problem). Any help on this would be appreciated. Like I said, I am new to working on c10s and everything. Sometimes, things aren't as straight forward as they seem with old vehicles. Thanks in advance for any advice or pointers.