You should have put this under the performance talk section for max coverage .
But from recent personal experience I can tell you that there's a massive difference between the output of that engine compared to today's version with the same cubes.
Your helm is also portside which means that if you go with a complete re-power package you'll have to get a unit with counter rotation but you may be considering retaining the Volvo unit . Is it in good enough shape to handle the boost in power ? And if it's not a trimable unit that's something you're going to miss.
You have a lot of work ahead of you for sure but they're great riding hulls . Job #1 , get that fuel tank out !
Just because something's old doesn't mean you throw it away !