A question about intakes

The LD4B has 29/64" holes for the intake, where the D4B has 27/64" holes...

I have a LD4B that has the part number and says D4B on that side.... check the holes for what size they are to see what it is exactly...

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LD4B:

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D4B:

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LD4B

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D4B:

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I don't believe I have ever seen a D4B with a part number. I don't think the part numbered LD4B's came out until later. (not immediately in 1966)