I got the intake manifold, fuel rails, and water pump all on. I also started on getting the wire harness installed. Next on the list is to get the fuel system figured out. My initial plan was to mount an AEM pump i have inside the tank via the sending unit hole. Then from the pump to a fuel water separator, to another filter, then to the fuel rails. From the fuel rails ill run a return line to a pressure regulator, and then back to the tank. Luck would have it though that the hole in the tank for the sending unit is not big enough for the AEM pump. So I need to either come up with a way to enlarge to sending unit hole in the tank, or bite the bullet and run an external pump.

ive seen some retrofit kits to install pumps into a tank that never had one fr EFI.....i just dont think an in-tank pump is "legal" in a boat. the whole design of the fuel delivery system in a boat is to minimize fuel spill into the bilge are. If you notice most if not all factory electric fuel pumps are mounted on or very near the engine. And the fuel line from the pump to carb or fuel rail is a hard line. In the even a fuel line breaks with an in-tank system it will just keep dumping fuel into the boat.
I did a quick search on the net and found this excerpt:15. Fuel pumps on a marine engine must be designed to not leak fuel into the boat. Many are double diaphragm. Today most engines have electric fuel pumps. The pump must be mounted on the engine or within 12 inches of the engine. This minimizes the amount of fuel line that is under pressure. It also means that unlike newer cars the line from the tank to the engine is under negative pressure. In other words, the fuel is sucked to the pump rather than pushed to the pump. That way if there is a leak the engine just starves for fuel and stops. The fuel pump must be fire resistant.

16. Fuel lines from the pump to the carburetor must be metal or USCG Type A marine fuel hose. This hose is fire resistant. The hose from the tank to the pump can be USCG Type A or B. Type B is not fire resistant and is hard to find.

Thank you for that information, I will go with an external pump. It will end up be easier too, I just need to pick out a pump now..

Have you looked at a corvette fuel filter ? The filter has the regulator built in so you just run a line from the pump to the filter , a return line from the filter back to the tank and then one line to the fuel rail. If you are using HP tuners ( the only one I know) find a stock tune for a later model truck with a single line to copy the fuel curve after .

Curious, why not go with a 6L or 6,2L as I think the block are all LS? correct me if I'm wrong.

just my guess- cost and dealing vvt and dod. If you blow up old 5.3 you throw it in the gutter and go buy another.

He stated on another forum that a 6.0 or 6.2 may be in the long term , but for now he is running an alpha and doesn’t want to buy a bravo. (I had the same question)

Corey331 and mgdoors have very good threads on there ls installs and the issues/fixes they ran into with builds and rigging. I suggest you deep dive.

as far as fuel pumps and etc for any decent ho engine, lots of threads on normal engines. Ext coast guard approved pumps, how to rig snd make return, etc

i may have spelled those members name wrong but will be close.

I’m on the downhill side of this type of swap too.

did you upgrade the main and connecting rod bearings? The engine will be higher revving rpm for Longer than a car. Look at kings xp (what I did or clevite h)
new pistons and rings
Deleted dod and put in ls7 style lifters
trunnion upgrade
I had to get a flywheel plate and a big merc coupler and bell housing.
did the external fuel pump (aem from summit) and dbc throttle body.
raw water pump is tricky I did the marine engine depot thing with a crank mounted Johnson pump with the mounting bracket and bushing.
running closed cooling like crusader set up their 6.0

Guessing you know Volvo has adopted these now.
I got a lot Of inspiration from ilmor and crusader but plenty others like Volvo running these now.. irocx said he was fixing his raw water pump with bracket.

Eventually the plan would be to put a 6.0 in here. I already had this motor from another project though and I will still be running an alpha 1 for the time being. I really wasnt even planning on doing this swap until someone made me an offer on the old SBC 350 set up.