First off, let me say hello. I am new here.
My question is, does anyone on here have any advice or experience with adding a pro charger to a 7.4 efi or maybe it's a mpi, I don't remember, 310hp. It is in a 99 212 Islander. Stock. I am currently running at about 60mph non gps. I really want to go faster. I have about 180hrs. Any comments please. Thx

Buy a bigger/better engine. Some will tell you that you can "get away" with the Procharger on a 7.4 motor, but they are just trying to sell you a supercharger.
The 7.4 motors have cast internals & cast internals don't like high cylinder pressures.
Your best bet is to sell the 7.4 motor & re-power with a 502 MPI or a 496 Mag HO.
Personally, I'd look for a nice 540 in the 600 hp range as long as you have a bravo one drive. You'll get better performance with that plant & you sure will go alot faster! Probably too fast!
Ofcourse I always have believed excess is barely enough. Praticality wise, I'd opt for a 496 Mag HO. That will put you at 425 horsepower & you'll probably see about a 10 mph gain, if not more.

Find a takeout 502 MPI, or a 406 Mag HO complete.

Then you still have your engine to sell to recoup some of the costs.

Probably end up cheaper, plus much more relaible.

You will also need hyd steering to go to much faster in a 21 footer

Hello,
First off you may want to make sure your getting the most out of your prop. That boat should run about 65 stock. If you really want to go fast and stay reliable I would drop in the bigger engine. I have a 502 carb in a 232 Islander, currentlly going 76 on the speedo.

GPS 76 or Baja speedometer 76? How many horse?

Well when I bought the boat it had a 21p mirage on it. I was hitting and 4800rpm and doing about 58-59 non-gps. I did some research and found out it came stock with a 23p mirage. So I got that prop this season. now I have not been able to really do a wot run yet. I usually have a full boat with 8 people and all the gear and beer. But over Memorial Weekend I got the boat to 59 with 8 people and all the gear on the 23p. took forever to plane thou. Two weekends ago I got some bad gas and ran like crap, then lost the impeller. I agree I should be able to hit 65ish.

How much do you think i could get a take out 496 ho or a 502 mag for? how much do you think I could get for my 7.4? thanks for the help.

502 $7000ish and $3000ish for you 7.4, these are pretty rough estimates though.

Now do you think the motor will be complete or will i need to install a fuel system or will mine work?

it will be complete, in fact, PM "OFFTHEFRONT" here on OSO, he did have one for sale.

Not to sound mean, but you would be better off trading into a boat with the 502 or 500hp.The bad thing about boats is you'll spend way more on them than you'll ever get out of them. They say that's half the fun but I say bullsh*t!!