Dang Mikey, your brutal and clairvoyant!!!
Actually, I was responding to this thread about 13 hours ago until my connection dropped due to some issue at ComCast so I just went to bed
About the prop, it sounds like wallball has a Bravo 1 where I have the Bravo 3 so I'm not going to be much help with the High Five...

, but I do have my opinions and they're right in line with ShabahZ250 and Z202 posts, anyway.....
Hi wallball and welcome to the club!
Your poor takeoff could be from a few issues but I agree with our other members in that the motor is having a hard time turning the prop due to being over pitched or out of tune may be the main problems here.
Trim tabs are not the issue here or the solution, unless you have a weight balance issue. We have them and I only use them so I can reduce the planning speed once under way while trimming the outdrive for best MPG and to help balance the load when we are carrying weight. I find most of the time the outdrive trim works just fine.
As ShabahZ250 said, insure the motor is performing as it should, then put her in the water and with no more than two people aboard and a 1/4 tank of gas, run your boat up to top speed and recording the RPMs at WOT (Wide Open throttle). The 7.4L should be turning around 4200 - 4600 at WOT. Once we have some data to work with, then we can determine the best course of action.
Like Z 202, I suspect a lot of your issue is the High Five. He's right, it's designed for a faster holeshot by providing a better "bite" without ventilating but it may be over propped for your Z240. Again, without some more information, it's difficult to determine this.
WetWilly [/SIZE][/FONT]