AFR SBM heads (supposedly)

If you mean this cut right here, 1.833”

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That's about the same as mine were last year. I sure wish they would leave them a little smaller than that for the 2.02. Your choice of 2.055 should work good. Gives a little room for hand work before the throat gets too large.

That view of the SM head looks just like the bowl cut on the AFR. Hmm....