Slowrider,
Trying to line an engine up with a tranny shaft is just plain torture! ('least it always is for me!)
Suggestion for your post-rebuild installation: remove the tranny from the chassis first. If your truck has a 3-speed, that's a light little gearbox and is a heck of a lot easier to fidget into place than a couple hunnerd pounds of stovebolt swingin' from the ceiling!

Engine in chassis first, then install the tranny.
'Nother tip: get yourself a couple of long bolts the same size as the tranny to bell housing bolts, and cut their heads off and put "screw-slots" in them to make:
Guide Studs!
Use them in place of the upper tranny bolts when re-installing the tranny, and it will help support the weight of the trans, leaving your hands free to "adjust" the angle of attack, as well as rock the u-joint yoke back and forth to line them splines up at the clutch plate!
Once you get the tranny seated and the lower bolts installed, then remove the guides and install the uppers.
(This trick also works when you've got a heavy 4-speed on a floor-jack! Good for cylinder heads too!)
Nice shop! I can't even move around in mine; and that's before all the junk ( I mean "treasure") went in!
Frank