My buddy has a 1988 Scarab III. Originally was a 370/trs boat. Previous owner had the 370's rebuilt, and Im sure they upgraded the cams, and they installed roller rockers. Still running stock merc exhaust, and q-jet carb, GM High rise intakes. Anyways, he just bought the boat, and it came with 24P Bravo props. He's only getting about 4200 RPM trimmed out, no tabs, and a clean bottom. His speed is about 54-55 max. I suggested going down to some 21P props, to get the engines in thier powerband, and take the load off them. Out of the 3 sets of props I have, which do you think should go on first???

22P Hydro QIV
Quicksilver mirage 23P (not Plus)
19P Revolution 4's.

Here she is

I would say the mirage 23.A mirage plus would probably be better though.I think you'll just blow the 19 revolution out of the water.I have no experience with the hydo prop.

OK when I bought my III it had crate 502'. /750 HOLLEYS. stainless marine II exaust TRS drives..I did alot of prop testing...had 19''-21" 23" & 25" mirage plus.. then I tried Q-4's..22"- 26"..best prop hands down was a Q-4- 22" pitch.. boat ran 58-62 mph on gps..hope that helps, The handling and midrange also the best with the Q-4"S...Dave