Running heavy weight

I have a question. I have an 07' X45 with the LY6 engine and a 14x14 prop. I hear people on here running crazy weight with their boats and wonder why it seems I am limited to around 1600lbs plus factory ballast. I know I have a lot of gear on board but with this set up and 4 people on board it really starts to take awhile to plane and if I push these limits sometimes it won't. Is there anyone out there with a similar set up that could give me advice. I know the 45 is a big heavy boat but I hear of X-stars running with twice this weight propped and driven with the same engine and wonder what gives. Granted I love my wake but I've ridden pros boats like Gerry Nunn's whose wake was insane and I think it would be fun to hit something like that occasionally. FYI I run 500 lbs in steel in the nose plus 400's in the back plus two fat bricks towards the nose which weigh 155 each. I set the tab at 3/4 down to get the rampiness I like. I am not 100% on that prop, I think its right. I switched from the factory to a 14x14.75. Wanting even more hole shot I upgraded to my current one maybe it's a 14x14.5 I will have to verify that and get back to you guys, but it was what Eric from OJ recommended. Are the stories with Xstars running 4k for real?