[Spits] Sputtering when hot above 50 mph

[Douglas Braun]

Did you ever resolve the potential fuel flow issue?

If not, here is one test to do:  Disconnect the fuel line at the carb
input and route it to a  jar or can.  Disconnect the ignition so the
engine cannot possibly run,  Have a helper crank the starter for a few
seconds.  You should see a series of solid spurts of fuel from the end
of the line as the engine cranks.  Even at cranking RPMs, the pump
should be able to supply more fuel than the engine would consume at
full power.

Also check for any crud blocking the input fitting on the carb.  I
think the Strombergs have a strainer there.

Doug