I have a Holley 4bbl, on my 390. On the passenger side, behind the choke, I have a plugged hose coming out of the carb. Is this correct or is this the what is causing me to vapor lock at high RPM's?

I am also thinking of switch to a maual choke. My father has manual chokes on all his classic Chevs and he never has issues. Mine seem not to work, until you feather the accelerator, when its cold. Anyone have any suggestions, with these two topics?

 

The large vacuum port on the rear side of the carb can be used for PCV or power brakes. Your set-up may use the intake manifold for vacuum so it may not be needed. It will not effect the lack of fuel at high rpm's. This is caused by either the floats being set too low, weak fuel pump or partially clogged filter more than likely.
Your chake may just be out of adjustment.