Th400 won't budge after engine rebuild

[Mrturner1]

I have a 1970 C 10 with a freshly rebuilt 350 and turbo 400 transmission that was running and shifting perfectly before I pulled the motor out. I got the motor back in and bolted to the transmission with a new 2500rpm stall converter, new adjustable shift modulator, Derale deep trans pan and new trans filter. Also installed new B&M light truck megashifter and all linkage.

Here's the problem, when I started the truck to back out of the garage, I put it in reverse and nothing happened. No think, no rpm drop, and nothing when I gave it gas. Tried every gear, nothing.

Now, when I put the stall converter in, I put a quart of fluid in it and slid it on until I felt a nice thunk, rotated it and felt another as it slid even further on. When I bolted it to the flexplate, it had to slide out towards the engine a bit to bolt on, just like it's supposed to.

Here's the part that concerns me. The Derale deep pan holds 3 1/2 quarts more than stock, so the pan is fairly deep. It came with a filter extension to compensate for this. With the stock pan, the filter sat flat (parallel to the trans and ground) when it was on properly and bolted to the bottom of the trans with a single filter bolt. With the deeper pan and new filter extension, when the filter was installed, to get it to bolt up like the stock one it had to be tilted at an angle ( not flat or parallel to the transmission at all ) in order for the filter bolt to thread into the transmission. I can't see putting a trans filter in and not using the bolt. That would mean the filter is just hanging there by the filter extension.

Any thought on this filter thing OR why my th400 won't budge? It worked great before the motor came out. I checked the fluid while it was running and in park, shows fine on the dipstick. Fluid is nice clean red in color.