Not without having the hull redone, ive see a few at the nat. jetski drags that had 4.3 in them, but they were pretty much 100% custom boats. What year and size are they? Most of the mid to late 90's 2-strokes can make serious power for their size and wieght. We had one that I raced in HS that made around 250hp and with the right setup could do over 80mph. Even my dad's Polaris Genesis made 215hp with a reed and head kit, and exhaust.
2000 Sea Doo GTX (both of them), I don't know anything about the engine except it's a 2 stroke and it's terrible in the performance department. When you say get "get the hull redone" are you just talking about glassing in new mounts?
'91 Bronco 351w, ZF5, D44 TTB, 9" rear swap with disk brakes, 37" toyos, method wheels, mastercraft seats, A/C and heat