Plugs look ok to me, but it’s either spark or fuel delivery..
Try a spray bottle with gas , shot into each carb and see if it picks up the dead cylinders.
Then try disconnecting the wires without a rag or pliers, you’ll know if a boot is leaking spark right away. Ha ha.
I would replace wires and plugs before digging in to carbs if above test with fuel shows nothing.
My wires were bad , same setup. Clean up the coils electrodes and dielectric grease inside the boots only.
Good wires will CLICK when installed . Tired ones will not.
Would not be a bad idea to remove the coils and clean and check the bolts and mating surfaces that holds them on to the block.
That is the grounding source.