Originally Posted by Chevrolet4x4s
Wont having the outboard carbs blocked off cause fuel distribution problems at WOT?
No. and it is a sure way to eliminate a possible vac leak in the outboards when working on a problem.
I've been thinking a little; and I wonder how well the intake manifold is sealing to the heads (if this was just put together?}. I'd look closely at the angle of the gasket surface to see if the manifold sits at the exact same angle as the head surfaces. It might have a leak at the lower parts and be drawing vacuum through the lifter galley.