Will 17.25 X 29's work?

Possibly, but I’d have to cut them down to 17”. Max dia on SCX-4 says 17”. I’d have to talk to Brett to see what that would cost.

You have a set you want to sell I assume?

Yes I’ve tried a handful so far. 30x15.625” maximus, 30x15.5” bblades 5 speed, 30x15.5” bblades 4 speed, 30x17 round ear merc cleaver, 26x16.5” four blade cleaver, and now a 30x17” 3 blade cleaver. I’ve gotten very mixed results. The best slip numbers I had were with the four blade cleaver. I’ve only ran the 3 blade to about 3500rpm, and the slip was over 40%, definitely not a cruising prop but I need something that will not lift the stern. I mounted a go pro in the notch on my boat pointed directly at the lower and even with the propshaft being just .25” below the bottom of the boat you can see the water hitting the front of the lower about 4” above the propshaft

my goal was to have same pitch x same diameter 5, 4, and 3 blades to compare results.

There was a cut down hering in the classifieds I just noticed and was going to call but looks like it’s gone already. From pictures I’ve seen, hustler 29 rockets with the ilmor Indy drive or mercury nxt appear to have similar x dimension and smaller diameter 5 blade cleavers.