Ok Gents,
I just watched the Official Edelbrock CD that came with my carb again & here is what the Ol Vic's Technician has to say on the procedure.
looking at the carb from the front,on the left is a slightly higher port than on the right, this higher port is "ported or timed" vacume as this port is (above the throttle plate),the Tech says this port is to be hooked up to the vacume advance on the dist.
the lower port on the right is manifold vacume (below the throttle plate)and is used for the modulator valve on an auto tranny,if ya runnin a standard tranny this port needs to be blocked off.
And of course the large port in the center goes to the PCV valve
Hope this helps,
Tim
