What will that cost you???? I can tell you it will get a good 1, maybe 2 mph.........is it worth it?

Your only reasonable options are:
1) Leave it as is.
2) Pull the stock power and install a warmed over 383, replace it with the original power when you sell it.
3) Sell it and buy a faster boat.

Of the three, 1 &3 are your best bets...

I don't think its even a power issue with the Montery at this point. Its kind of like modding a Lexus GS350, can it be done? Sure it can and it'll probably go fast too, but it wasn't ever intended for that and no one will buy it when you're done with it. If you are going to do anything, put a Volvo 5.7L in and leave the EFI alone. That year of Montery wasn't available with a carb so don't put one in, people will look and wonder what else has been messed with. Ever seen a lifted truck and walked away from it on the chance that its had the crap beat out of it and just looks pretty? Either sell the boat and get something that was intended to run, or do a 5.7 swap and be happy with what it gives you. My real world $.02
If you really MUST keep the boat and must go faster, a 383 efi motor and captains call would allow you to keep efi and a stock appearance with a lot more balls. Might not absolutely kill resale. Put the 5.7L volvo cover on it when you go to sell

scorpion 383 cubic inch available from Mercury rated 400 HP

As stated that SX will take more hp than a Bravo so no worries there.

Also as stated a 320pshp Volvo 5.7 might be a good swap.

Years ago I swapped out a 250pshp Volvo 5.7 to the 320pshp version. Very simple and I picked up 6mph.

If you do go Merc you have to use a Volvo bell housing, motor mounts and I believe one other thing but I can't remember right now.

This is absolutely the best option, small block Chevy's are damn near free (ok, that's a little exaggerated). You can always transfer the accessories...Look for one.

Oh, and yes, the outdrive is fine. As for weight, any set of decent headers pretty much makes up the weight difference.

+1


Volvo builds a great drive that can handle power well. They also put some thought into protecting the drive rather then engineering catastrophic loss into the product. They put a sheer coupler between the upper and lower shaft that lets go in order to save the drive. We've had 600hp in front of a DPX with years of abuse and no probs. I believe the coupler is roughly a seventy dollar part and only takes an hour or so to install if ya lunch one . . . . . Have at it!

30 to 40 hp will not even be worth the money

Add over 100 or leave it stock

Again, buy a new boat, yes you might have to sell yours for less than you want but you will save more than you lose on your next boat.

Thanks for all the input, I like the captains call most of all so I think I'll look around for a 5.7 setup and then add the captains call.

I can't post to the WTB section. If you know of anyone selling a good 5.7 setup LMK

Ok, one more idea, how about this:

SBC 406, B&M blower and intake manifold, double pumper carb, roller motor. 8:1 CR, 1973 vintage. Been dyno'd at 550HP/595FT# with headers, obviously will be restricited by the penta manifolds..

Big question on this one is whether or not my manifolds will bolt up to it.

Thoughts? Thanks for the help.