I know this is not exactly the info you are after, but I Repowered a 6.2 Seafarer Venom (same hull as vagabond) with a 200 Suzi and I would have thought you'd get more than 42 kts out of your combo. Fully loaded, I would get 38 kts no problem and it would do 40 on the way home. I settled on a Solas 3 blade 16 x 19. I tried a few sizes, but this was best all round. I did achieve 44 kts offshore with a Solas 4 blade (sorry can't remember the size) but it was otherwise a bad match. At normal revs, you could hear the motor working hard and fuel economy was crap. Good luck getting it sorted