Hot Rods No reverse

I drove my '40 pickup for the first time today after a 4 year build. I drove it out of the driveway down the road and made a U turn to come back.
As I tried to back it up, there was no reverse. It's a new (rebuilt) 700R4 with a Lokar shifter. Do you think it could be a shifter adjustment? I can feel it go into every gear smoothly but when in reverse, nothing happens.
The damn tranny also leaks. The level was full when I drove it.
Any suggestions?