Im running a 509 500 hp in my 260 fx and turning a 25 pitch prop 1.5 to 1 brovo drive, 4000 rpm cruising speed is 55 mph real calm in rough water with that deep hull, at wot i can only turn 5100 rpm and run 71 mph. How can I go faster with out using a blower? my 502 is 30 over, I have merlin comp 320 heads, Dart intake, and a 850 double pumper carb, roller cam and rockers, and all msd ignition, stainless marine Headers,

Save up and do the blower!! Thats about all you got left! Or work on set up.

Skydog

I would say go down in prop pitch..
If your only getting 5100 rpm's out of that motor ,then I would say your still missing about 500-700 rpm's that you would have left in it.. Just my 2ct's.