RRat, Call Capt Chad Dufrene -
http://www.dufrenesguideservice.com/4436.html
He has been running your exact setup.
He posted lots of performance data on another site:
His comments pasted below:
25 Extreme Performance Numbers
Finally got through my break-in period and got to let the big dog eat. First let me say that Jimmy and Johnny Majek have hit a home run with the 25 Extreme. Being a fulltime guide for the last 14 years and a tournament fisherman I have had the opportunity to ride in and own many different boats models. Up to now the 25 Extreme is far superior than anything I have rode in so far. Holeshot, midrange and top end are great with the 300 Yamaha V6 fourstroke. The boat does not squat and jumps on plane at 2000 rpms without the trim tabs. This is truly incredible for a 25ft boat. I would not have believed this but I do it all the time and everyone is just as impressed as me. Here are the numbers with several different props:
Full tank of fuel, Trolling motor on bow, 4 Batteries and on board charger
2 people(Tournament load)
160lb Captain
265lb passenger
Mercury Rev 4 23pitch 3000rpms - 36mph
Best all around prop
4000rpms - 45mph
4500rpms - 40mph
5000rpms - 57mph
5600rpms - 64.7mph
0ne person 160lb captain 5800rpms - 66.3mph
Bravo 1 24 pitch 5600rpm - 63.5mph mid range not a good as Rev 4
Mercury Tempest 23 pitch 5800rpms - 63.4mph
Bravo 1 22 pitch 5900rpm - 63mph
Yamaha Saltwater series 23 pitch 5800rpms - 62mph
The WOT runs were tested with the jackplate at 1", 1 1/2", 2", 2 1/2", and 3" heights with each prop. At the 3" height I could get more RPMS but not more speed all the while careful not to get over 6000rpms. The best speed seemed to be with the jackplate set at a 2" height and trimmed out all the way up. We tried several figure eights and hard 180 degree turns at 30, 40, 50, and 60mph trying to make the boat slide, bite, our blowout and each time she was as smooth as a babies b*tt and never slid, bit, or blew out. The boat does not fall off the pad and bite. She holds the turns while staying up on the pad and does not slide. I put 12x12 Lenco trim tabs and the holeshot is stunning with the tabs down and engine up on the plate. Thanks Jimmy and Johnny for making a saltwater Ferrari sure to impress my clients this year. This boat is truly a pleasure to drive. I know there are many great Texas made skiffs and flats and have not rode in all of them. I can tell you the 25 Extreme is quite impressive.
Hope this helps.