Stumpy

Just bought a 97' 230 explorer with a 5.0L Alpha one and the prop that came on it was an aluminum 4 blade that I cannot read the diameter or pitch on. The owners manual says WOT is between 4200-4600 but unless my tach is defective I cannot get over 3000rpm. I put a SS 19p prop on it and gained about 5mph (40 mph top speed) but still didn't get over 3000rpm... I know I'd gain 200-300 rpm for each degree of pitch I lose but to get to 4400 WOT I'd need like a 15p prop... Does anyone know the size of the prop that would have come on this boat? What kind of problems does running a lower RPM do to the engine??? Thanks

I just bought a 95 230 Explorer and the Bimini has zippers on all four sides and snaps on the boat that makes me think there was once canvas or plastic sides for this boat. Can anyone recommend a place to buy original canvas parts for this year model?