[carmine]

Hello Ted

The cause that I have found to this out of sinc problem is that the hole drilled in the center of the intake that holds your center pivot bell crank has been drilled aprox 1/4 inch out of center to the carbs.
Had same problem on my carb sync and that's what I found was causing that problem.

If your using air fuel gauge with o2 sensor
11-12 air fuel readings is what you want to see at idle
Anything higher tends to cause lots of popping and lag on transition

What idle air corrector are you running?

On your water pump, what water pump pulley ratio are you running?
Eg) one to one or underdrive ratio as compared to crank pulley.
If underdrive I have found that more cooling happening on one side bank head than the other and gave me richer reading plugs on one side vs the other.