Bob has sadly passed, but his son Brian and company still run American Diesel in Kilmarnock, VA. They are ever helpful.
Assuming you have the usual Borg-Warner transmission, there is plenty of expertise there and here on TF to give tips like using long bolts with the heads cut off in the top holes of the tranny to help slide it aft once all the other bolts are removed.
FROLIC (2005 MainShip 30 Pilot II)
Panama City area