[FireSale]

There is more information in the carb section of the Accepted Products Guide. The copy I have on hand is 2017, so check the current one. SS/AM-EM are listed under American Production 4-Barrels and just says "In line/Three Prohibited". The notes for that section are below. Sounds like CM can use anything on the whole list up through 850. With three prohibited sounds like two is OK but no six packs.

I'm no tech but I hope this helps.
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American Production 4-Barrel Carbs
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Any of the accepted 600, 750, or 850 CFM carburetors listed above may also be used in these classes. For these applications the throttle bore, venturi, throttle shaft and plate dimensions listed apply for these carburetors only.
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Any carburetor manufacturer represented in the NHRA Blueprint Bulletins; i.e. Holley, Carter, Rochester, Autolite, Ford, Straumberg, etc. is accepted.
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Any carburetors produced by an accepted manufacturer plus the specific carburetors listed below.
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For any accepted carburetor not specifically listed (or noted) any size throttle bores and venturis as produced are permitted; no size limits apply but no modifications from the as produced throttle bore and venturi dimensions are permitted.
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