Originally Posted by sweeteye
Certainly do not want an underpowered plane or an unbalanced one.....
Judging by your first (fuzzy) picture, looks like you'll have around a 14-15" wingspan? If so, you will CERTAINLY NOT be underpowered with the P-51 motor. You'll have enough to pull you out of "critical" situations, and you'll have plenty to do whatever acro the rudder and elevator allow.
What kind of wheels are you using? Heavier wheels may help if you can't get a good CG by stuffing everything up front - right, Pete?