[HWYSTR455]

Another thing to note is that Carter, and believe Edelbrock, rate their' carbs' CFM differently than Holley, at a different mercury, and the same CFM rating by Holley on a AFB would result in too large of a carb. (AFBs having smaller numbers for rating that Holleys for same flow)

That can throw your sizing off, and, hence, your secondary opening rate.

Looks like Edlebrock may also offer the black ones.

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