Seems like these values are going to be a little more elusive than I had previously thought, David, but I did manage to find the following statement in the 737 Maintenance Manual. Whether the 9 degree limit is an absolute maximum, I can't say however.
"Elevator Authority and Command:
If the autopilot is in the pitch go-around (G/A) mode, the authority is 9 degrees. If the autopilot is not in the pitch go-around mode, then the autopilot uses these signals to calculate elevator authority:
#Total air pressure
#Static air pressure
If the flaps are between 0 and 7 degrees, the authority is limited to 3 degrees."
Of course, the Stab Trim system will add significantly to the total pitch authority.
P.S. By the way, will the autopilot in your simulator be controlling pitch by both trim and elevator movement? (Can't say I've seen a desktop sim A/P operate the elevator before, but rather, through a high speed trimming system... presumably for simplicity).