Trimming it up with that prop isn't going to get any more mph, it was bouncing off rev limiter already.
50+mph in that boat with a 19 pitch prop is very good, it could be going even a bit faster on the GPS, boat gauges usually read a bit low.
http://www.watercraftservices.com/Propwiz.php
If you care to tweek your prop a bit Brandon this site is what I use for our boat and it works great. From the specs I knew about your boat I got that you should either a 19 pitch for mostly watersports, or a 21 pitch for performance/watersports. So you should be good to go with what you have but with only a few people in it in good conditions you are going to be bouncing off rev limiter at WOT. Looks fun though, sounds good too.