I ain't no guru, but if you're talking about a 250 stock intake from '66 then as far as I know EGR didn't exist back then. Since the intake's bottom is closed, I don't see the need for a plate unless you want to setup some kind of manifold heat contraption.
Joe
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'67 Chevy C20 fleetside, 250 inline, 3 on tree, heavy duty clutch and brakes, heater, steel bed floor
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"Tighten until the stud snaps, then back off half a turn."
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