Edelbrock makes a slightly oversize thin metal plate for it's manifolds. Looks like an oversize 4 hole gasket. (or is it 1 hole open?) Anyway, the purpose is to seal off a square plate Holley when used on spreadbore intakes. Specifically Edelbrock Chevy spreadbore intakes. Ones that are drilled to bolt either type carb. Anyway... I wonder if one of these plates would seal the carb, as the plate is a little larger than the base? Then the exhaust crossover block off plate would keep any EGR hole that is not blocked, from venting around the carb/plate. Not that I care for this intake, but just a thought to solve this issue.
A simple over sized plate would have covered that hole under the carb. But if you're limited to OEM intakes, why even bother with the 83-85 intake ? I'd be using a C9OX intake which is identical to Edelbrock's older F4B & Ford's current A321. The C9OX is legal for what you're doing. I've got two buddies who are running the 351W version in stock cars.
