Here's my experience:
In many cases the D-jet and K-jet fuel pumps can be interchanged. K-jet
requires higher pressure (65-70 psi) than the D-jet (28-30 psi). My daughter
is using a D-jet pump in her 1980 245 and it is working OK.

Sometimes the reason the pump leaks is that the rubber ring around the
electrical connector is dried up and shrunken. It will swell when wet with
gasoline. I have put them on seeping slightly and had them drip for a night
and then stop. I realize this is not the most desirable situation but the
cotton pickers are EXPENSIVE!! And it did pump fine.

You DON'T want to use an electric fuel pump with carbs. The OEM Pierburg
mechanical pump puts out 3 psi, exactly what the carbs want and not enough
to push the float valves open to flood them. It is hard to get a regulator
set that low reliably and certainly with a pump like the injection pumps.
Now the in-tank prepump that puts out around 5psi could probably be regulated
in a satisfactory way. The last regulator I had blew its diaphragm and
dribbled gas all over my engine. No fire but it was sure scary! Later I
found that the pump supplying it was putting out exactly 3 psi. Don't know
why the regulator blew - it was NOT a cheapie. I took it out and threw it
away.
--
George Downs Bartlesville, Heart of the USA!