I had a similar problem, The van would run a bit, then cut
out, run a bit, then cut out.  What it turned out to be was
an intermittent fuel pump failure (this was your good first
guess).  What made it hard to diagnose was that with the
Key turned to the "on" position I could hear the fuel pump
ticking so I (wrongly) dismissed that as a cause of the
problem.  Try and listen for the fuel pump ticking and then
when the engine stops, do NOT turn off the key, but
again listen for the fuel pump.  The problem was
diagnosed by a mechanic with a fuel  pressure gauge.  IF
this is the problem low pressure carb fuel pumps are
cheaper than the high pressure FI fuel pumps.  I put a
fuel filter BEFORE the fuel pump and after the fuel pump.

FWIW, I also have a carb (Solex) and the 009 distributor.
I have found that the Pertronix electronic (contract
breaker) points have works well and was easy to install.
http://www.vintageperformance.com/retrorockets/

Good luck,  Malcolm

> Vehicle: a Weber (I believe) single carb & 009
> mechanical advance distributor.