i'm currently running 30x17.5 (5) blades and can spin them to about 5900-6000rpms at about 100-102mph, i would like to lower my rpm to about 5600rpm where my peak hp is. should i go to a 31pitch and will it effect my speed?

every 1 inch of pitch equals approx. 200rpms..try a 32"....that being said,every set up is diiferent;but that should be close to 5600rpms

I was always under the impression that you wanted to have a few 100 Rpm's over where your peak HP was.

If you can turn the 32's 5600rpm's then get em' labbed,5750-5800 labbed should get you to 105!

Up the pitch and work them from there.