After reading up a bit and watching comparison videos I'm switching my carb spacers to a 4 hole type.
I had installed
https://www.edelbrock.com/carburetor...nate-8724.html
Installing today
https://www.edelbrock.com/carburetor...nate-8723.html
I like the wood composition more than the Phenolic canvas due to the insulation properties being better.
From what I've gathered the Open spacers when used on the 4 hole intakes screws up the signal to the carbs due to the reversion. Made even worse with my long duration cam.
We shall see...