1991 4l80e no gears

[BurbFam]

Hey guys, i've got a 1991 v2500 5.7 TBI with the 4l80e. i pulled the original trans do to hardshifting, and the rear main was leaking anyways. found a used trans out of a 93 motorhome with "36k miles" but it was a 2wd so i had to swap the output shafts. i'm pretty confident with how everything went back together.

i dont know how long the trans had been sitting but the truck hadn't been started for a year. finally got evertyhing put back together and started it up yesterday, it took a bit of effort (even with a new battery and starter) just to turn the motor, like something was holding it back, but once it "broke free" it idled and revved fine. but i have no gears, nothing forward and no reverse.

is there any wiring issues that might cause this? my research brought up possibly a bad pump, maybe thats what was holding up the motor from starting? won't have a chance to pull the trans lines off the check for flow till next week, hoping i can get some more info from the minds on this site until then. Thanks.