Learn how to measure prop to pad first off.

forget "dots" and etc.. get out a good level, measurin' tape, straight edge and start here:...

http://www.stevescustomprops.com/faq.html#How_do_I_adjust_the_Prop_shaft_engine_height_

ya want ta start with 3 1/2 inches between A and B.

You say you haven’t loaded everything in yet…..Although it makes no sense to me, I’ve spoken to 2 people, 1 from the Elites and 1 boat repair shop owner, who lost speed when they lightened up with lithium battery’s. Something to do with hull design done expecting more weight.

Ok,
There's a lot of guys here who've setup a lot of boats. Ignorance is not a sin, we don't know what we don't know.

IF
You want to find your potential, there's only one way to find it, might take you a couple of hours but it's time well spent, because you'll learn a lot about your rig and what makes it do what it does.

1. Put all your stuff in it. Fill up the gas tank, when you get to the lake, fill up the livewells. A boat setup light and dry will never run right loaded, but a boat setup loaded will still run good light.

2. Get a sharpie, you'll want to mark where you start on the plate. Bring a notepad to record your results. It's too easy to mess this up without writing it down.

3. With your full load at your current setting, go run it. Track holeshot time, and WFO speed/rpms. That's FULL power/FULL trim.

Now listen to your boat, it's going to tell you exactly what it wants. Is the roostertail higher than the motor cowling? Is the boat running flat to the water? Is the steering really stiff? Those are symptoms of being too high for your prop. Now's the time for small moves, 1/4" down until you lose speed, then back up a click. You must know what too high and what too low is, it's the only way to find just right.

And if you swap out props, you get to do it all again, no two are identical.

Ok sweet, ill try that the next few trips! water pressure is holding good, so I'll start lowering the jack plate a bit!

Take it too far and bring it back. That’s how you find just right

I have the same boat. It can fly, but as soon as you start loading it down performance will suffer. "9 dots" is the often suggested adjustment for the OEM Slidemaster for those looking for a bit more speed. IIRC, it came at 7 dots from the factory. But as mentioned, dots are really meaningless and you need to measure to get a baseline/starting point so you know what each adjustment (dot) does.

I would consider my '16 ZX to be a bit of an underpeformer, but I have triple units on the bow with M360 and FFS, plus the triple mount is heavy AF. Upgraded from the single Pole to a pair or Blades, and switched over to lithium batteries. Also moved from the Fortrex to a Ghost. I've upgraded to a Bob's JP which does helps (wish I had gone to the 14" though vs the 12") but in general with the tackle store I tend to carry around and all the extra weight on the bow, my ZX with a worked T1 is about a 65-66 mph boat at best. "Before" all the upgrades, it was a 72mph boat with a single pole, 9" flush mount and Fortrex only up front (lightly loaded).

I've cosidered trying some different props to try and bring back some speed, I have above mentioned T1 and also stock T2-25 as a spare. Actually I did try a Tempest 24P trying to see a bit more rpm but it was the older vented and didn't perform that great even with all the vents plugged. I also tried a Solas 23P but lost rpm and speed with it. Have heard guys run a 26 Bravo or a 24 RazorXL with good results, just don't want to get too invovled in chasing down props lol...

Oh, also be sure to check the throttle cable at the motor to make sure it's hitting full throttle. If you are getting 6K is likely is, but it's a somewhat common thing for it to be a bit off i believe. Make sure the throttle mark meets or just passes the triangle mark.