Had it out this weekend. The speedo is apparently already hooked up to the GPS. I just hadn't ever turned it on. It ran 75.8 to the limiters at 5300. So that is about 30% slip. Kind of a problem. Had it trimmed to about 4.5 on the indicators.

You've got 10mph missing...

I know. I'll find it. I always like a challenge.

Lots of room....wow. My standard legs are running about 14-15 percent on 4 blades

What were you running for tab?

you may have to space down another 1" for the 4 blades to work, or try some 5 blades P5x 29's would be a good place to start, did you have any throttle left at 5300?

Try maximus props first before you space anymore .

Tabs all the way up. No throttle left, but I when I opened it up it only took a few seconds to start beeping. So in other words if I were to keep it off the limiters I would have to back off a little.

My father had a 42, 525's, a/c, genny, all the BS. We tried everything. About 80 mph give or take a couple is all it had.

It seemed way under powered for that large of a boat.

My 04' 525 boat is at 80-81 max with standard 32's, standard length. I could not get the slip down either.
I would try maximus props as well. Ran a set, and they have bite. I think labbed 30' maxes is what's reccomend for that setup.

Do you have the boat?