Stacey, I think the NX750 is rated to a 135hp motor. I looked at the Tracker Marine 2001 site and it showed the boat rated at 135. I may be wrong. On that boat and motor I think the Lazer II 22p prop will work better. Skip
A 24 pitch was too much on my Nitro 180 with a 115. It's the same length as your 750 - 17'6"; but the hull was not as slippery. I'd suggest you get the dealer to start you with a 24" pitch.
Scott
P.S. I get the impression that Tracker likes to start out with props just one pitch too high to keep rpm's down a bit with new motors and new boaters. A very good idea!