Fuel Consumption

I am looking at buying a new used boat. It happens to be a 22' Sea Ray Pachanga. I have a nice 20' Searay Seville cuddy with a merc 4.3. Its junk filled with water from winter rains and instead of putting money into it I want my dream boat, the pachanga.
I can get the boat with 2 different v-8's the 350chevy or the 454 ford.
What can I expect in fuel consumption. I've heard 12-15gph for the 454 but I haven't found any figures on the 350.
Is the thirsty motor worth paying the extra $$ for gas versus extra performance?
My 02 tells me to go with the 350. I use my boat perhaps 12 times a year and probably run for 50 hours per year. So fuel could cost $2025, Yipes Hopefully, I will use this boat more, with its offshore design, I'll be out more locally on San Francisco Bay, so maybe 75 hours. I'm wondering if the fuel cost will be that significantly different to sacrifice the extra power.

I seem to remember using about 10-15 gallons per day with my 4.3. What does the average 4.3 consume and maybe I will have a more accurate read on how many hours I run per day.
TIA, Any advice will be appreciated.

 

in a day two merc 4.3 EFI's can empty my 125 gallon searay 27' tank easy

 

i have a ford 351 block

i have a ford 351 block, bijet carb, on a 20 feet V-hull boat, with an OMC cobra outdrive. with a total displacement wheight of 3500lbs, at 2800 rpms , 28mph (24,3knots)its consumption is exactaly 7gph. Hope that helps!!

 

diesel Phantom drive

there is a new drive system which burns 3.1 gals per hour with no loss in speed or performance. developed in Florida and should be on the market in your area by july or Aug

 

there is a new drive system (diesel) which burns 3.1.gals per hour with no loss in speed or power . this was developed in Florida and should be in your area by july

 

I believe the engine is either a 460 Ford or 351. The 454 belongs to Chevy. My 34 foot Donzi with a 454 and a bravo three goes 50 MPH and uses 12-15 gallons per hour at WOT.(4200-4400rpm) By the way I have a GM 4.3 litre for sale I believe it's a 1999 if you are looking to replace your old water logged one. Also what do you want for your old boat as a fixer upper???

 

Scott, what do you want for your 4.3. I think the boat and trailer is worth 2.5k. I have a new tandem trailer for it that I am going to swap with the tandem on the boat that I plan on buying. I paid 4500 for the trailer last year. Its made by pacific, galvanized, 14"wheels with spare disk brakes, and the full length guides. The trailer i should be getting is a ezloader roller trailer, painted but looks to be in excellent shape.