Still got that Syndicate? Jacuzzi WJ pump?
Know what motor was in it? What impeller? Most had a 'B' impeller.
A mild SBC- 325-350 hp would put ya in the low to mid 50's
Needs some hardware to push it beyond that...
18' saguaro bow rider was @ 55 with 325 hp (mostly stock 350 Suburban motor)
Dan'l