I shoot the same bow for target and 3D.  Way cheaper and you can get one arrow set up and stick with it.  If you can comfortably shoot the lighter bow then stick with it.  No reason to damage yourself trying to shoot heavier.  Spending your time learning to shoot what you can perfectly will go a whole lot farther than spending money on bows and extra equipment.  Once your brain memorizes the trajectories and you have great form your 3D scores will go up.

ok well i think you all solved my problem, im going to look for a way to sell my damon howatt bow, and look for a sweet shooting 50 pound bow. Any suggestions?