I am actually just running the Mercruiser cool fuel setup with factory 7.4MPI pump, never falls below 58 psi. Maybe that means my boat is pretty slow...

I have considered playing with it myself. I have a dominator flange on a mild 540ci NA. I really don't want to change intakes as this one is matched to the heads but haven't been able to understand if their 4500 flange setup will be too much for my power.

If I do the Sniper I plan on also running the D.U.I. Marine ignition. Did you run into any issues using it with the Sniper?

i am a long time boat wrench and when we built a state of the art 540 for our thunder i debated the latest fuel injection route and then looked at 2 boxes on the shelf one is failed carb parts and pumps the other much larger box is dead fuel injection parts and fuel pumps and regulators ........i am very happy with its awesome performance and almost instant starting it behaves well around the docks yet screams on top as a big block can at 6500 its a simple clean install and does everything i wanted the engine to do and the BIG one is its reliable and fixable with less than a 100 dollar carb kit that box of injection parts is insanely expensive if i dare add it up, theres a dozen ecu,s over 100 fuel pumps rails a couple hundred injectors no the be honest its mostly from fishing boats but what would i have gained when the beauty is simplicity and makes more power than i need ...... state of the are computers and sensors and screens on the dash in the boating world do not last a long time good luck with your choice

The downside is too much tunability and too many options at your finger tips.
Also too much info on the 7" screens
I find myself looking at intake temps, timing,map, TPS, compensation, AFR`s , IAC counts, etc etc .. so much info .. so many tables to play with. With dummy carbs you set em up and hope for the best. No compensation for weather, temp, load, no learning .. it`s just so simple :D

I really miss smelling like fuel while pulling 4 carbs apart to change jets to try to get a decent fuel curve. lol

Seriously thou I think the best part of EFI is setting up the safeties for water pressure, intake temps, oil pressure and temp and so on..
I throw a water pump belt (for example) the water pressure drops and immediately the engine goes into limp mode.. with a carbs you`re still running along burning down the motor frying the exhaust ..

Yes, but let's be honest, time and technology March onward and for good reason. We won't even be having this discussion in 10 years because everyone will be FI on this website. I'm hoping to switch this winter and I won't look back. I'll carry a carb with my in case something breaks down.......

None. But the DUI does require a 12g wire from the battery. I set up a power block on the transom and run all of the needed power off that bank of relays using the OEM wires as triggers. That ensures that everything is getting the power it needs.

Also, DUI recommends a spark plug gap of 0.055 which is ridiculous. People have had better luck staying under 0.040.

Doesn`t the Sniper have the ECU built into the TB?
I went with HP external ECU .. seemed like a better way to go .

I’ll be honest. 20 yrs ago or more, everyone said carbs are gone and we feel really bad for Holley because of this. Holley survived , and then some. Their fi did not save the company back then. It is a bunch of cherries on top now though.

Carbs still have their place for sure. So doesn’t FI.

Yes. Pretty much plug and play which is plenty for most of us. If it was an engine that I had a lot invested in to id definitely go with the MPI and fancy ecu.