hi there.
i dont know if any one pump will work for you but im sure someone here may be able to help. (i read some t-brickers talking about walbro pumps?)
(I'm having fuel deliveray problems because the main may have a worn check valve) im no mechanic but i dont think this worn check valve will cause your fuel delivery problems. the check valve can be swapped fairly cheaply.
the check valve as i understand it helps with hot starts.
in my k-jet i upgraded the intank pump with a (new) 740 pump and run the bosch main pump. (pulled from junker = 15.00?)
its a pretty high pressure the k-jet uses so i would think to find a alternative replacement you would be looking at $$$$$
i hope to learn from this thread myself.
if you could obtain a CI fuel guage it may solve your problems, did you measure the fuel as per bentleys at the return line? this may also shed some light on the fuel delivery problem.
good luck
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85 244 ti 222,000 83 244t broke odo, 85 244 19?,000 86 244 151,000 94 944 116,000

As I understand it, the main purpose of the transfer pump (it's correct name -- it's also known as the "prepump" and "intank" pump) has been to eliminate vapor lock. It's only pressurizes to about 3 psi (0.2 bar), but it ensures that the whole fuel line is under positive pressure, precluding the formation of bubbles (unless you've got a crack in the notorious, small 2" hose, of course :-).

You don't want to experience vapor lock, my friend. I had this chronically in my old K-jet 164s (both '73 and '75). What a pain. On a warm (not even hot) day, the engine would bog down and refuse to accelerate! Trust me -- love your transfer pump. Change it if it's bad, but don't look to bypass it.

And, by the way, if you're thinking of bypassing the main fuel pump, be sure to use a choice that can deliver the fuel adequately in terms of volume as well as pressure. It's easy to supply a carb, but a lot more difficult to meet the demands of a fuel injection system.

Good luck.