I have an 08 33 fountain lightning with 496ho's , 1.65:1 ratio and maximus 32x15 5/8, My performance sheet says it came with 33 maximus ran 84 and turned 5050 rpm. I find this hard to believe since with the 32 props on there i have not turned more than 4650 rpm. and run 79mph, both engines are turning same rpm. Any help would be appreciated.

That's because the performance report was based on the magic waters of the Pamlico River! ;-)

Fountain may have labbed the original props, as well. Call BBlades and tell Brett what your seeing - he can get you a few more RPMs with labbing.

Only 7,7% slip?

is that good or bad?

i think i have the original props

Well, if current props are 32's, and you have the original 33's - then put the 33's back on and report back.

i think the originals are 32's even though th sheet says it had 33's. 33's would turn even less rpm