View parts diagrams and shop online for FUEL SYSTEM & LOWER INTAKE MANIFOLD parts, 1995 Stern Drive 5 50FAPHUE. Offering discount prices on OEM parts for over 50 years. FAST $4.95 shipping available.
www.crowleymarine.com
this shows the low pressure one as NLA but the high pressure one is available, at a cost of $477. Take a look at Volvo parts, they used the same engine, see if it's the same price or less.
Just looking at the sheer # of NLA parts for this fuel, and ignition system, I wouldn't invest a dime into it. I'd start looking for a Ford 4bbl intake like I said above, see if there is a block off plate that you can remove to install a mechanical fuel pump, and get a brand new Holley 4160, they make one specifically set up for the Ford 5.0. Then look for a marine Ford distributor that can run the ignition system stand alone. Then put all this nonesense behind you and you'll have a boat that can be maintained and repaired by anyone. Sell off all that NLA stuff on ebay, make back some of the conversion cost.