You didn't mention it, but if the intake is iron, you have a stock spreadbore intake- casting #s varied a little. As you found, a square-pattern Holley doesn't fit well on spread-bore intakes. I suggest an aluminum Edelbrock Performer intake; it bolts on, fits both carbs and will run better with slightly more power & no drawbacks. If the engine is intended to be radically modified, other intakes might be considered.
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