[WFBowen]

In keeping with Prsh356’s suggestions, if the car will idle at all, try dripping a small amount of fuel into the suspect carb throats and see if there is an apparent difference in revs. Use only a couple of drops.
If nothing changes, pull the 2 plugs to make sure someone didn’t put the wrong (longer) reach plugs in there which would close the gap. Also double check your firing order 1432 to be certain 3 & 4 aren’t crossed.
Bill