need help from someone with old merc experance

[lathehand]

destroyer your right on about the heads.It's just a water jacket.When I said it'll scream Yes out of gear but in the water.The prop spins freely by hand and the prop size ie 13and3/4x17.I've tryed to rase the trim up it don't seem to make much differance.I't almost seems to me to I'm not gettin the high seepd circut between the carbs and distributor