Opinions

Usually dual planes feed cylinders in a "Y" configuration looking down at the carb flange. For example one side of the carb would feed the two outer cylinders on one bank, and the two middle cylinders of the opposite in a dual plane intake. Its a balance issue with air fuel ratio I'm not saying this is your problem though.
Thanks, so reading this correctly the manifold and carb while might be not giving the performance should not be the problem
When I shorted out the entire passenger side bank leaving the car running on just 4 cylinders as compared to shorting out the drivers side there was a very noticeable difference, car would almost and would id say stall but keep running when I tried the other side
I read that as maybe whats going on with this engine.......Im busy today but I will do that compression check and a cylinder leak down if I find a low cylinder......Thanks again to you and everyone else