Warlocker

I have a 2000 Warlock 25 SXT cat.It is running a Mercruiser 502 MPI hooked to a Bravo 1 w/low water pickup (no cone).It is spinning a Merc. labbed 28P Bravo,80mph(GPS) @ 5000 RPM when at WOT.The boat runs great and comes out of the hole like a rocket but wants to porpoise after getting the drive untucked at WOT.It has one spot the boat want porpoise but you cannot use the trim up or down from that point.I have talked to Carter at Warlock and he says tunnel plates will fix the problem.I was just want to talk to someone that has experience with tunnel plates before I drill 26 holes in my transomAny help would be greatly appreciated,thanks Warlocker.