IGNITOR I has given problems
IGNITOR II is a better option.
Check both IGN and FUEL to CYA.
Here is a film showing fuel percolation-https://www.youtube.com/watch?v=cadNfSNi_Oc
The spacers you see are most likely OEM aluminum, and will conduct engine heat to the carb fuel bowls. You need phenolic (plastic) spacers to cut down on the heat transfer.
Remember, this may also be vapor lock and/or blend separation on the suction side of the pump (tank to pump) also. If the rubber fuel lines are not ethanol rated, they can break down inside and cause a flow restriction too. Just a reminder.
MEL DIVISION - 1958 - 1960
MERCURY - EDSEL - LINCOLN
Present Location - (Subject to Work Release Requirements)
W (BY GOD) V - MBG - Eastern Panhandle
TAKE ME HOME - 81