H16 Mainsheet lower block size

I've read several past threads regarding the differences between the Harken 194 and the Harken 57mm Carbo mainsheet blocks on the H16. Most discussions are focused on the features of one block versus the other, but my question is, "All other things being equal, why not use a 40mm (1 9/16") block as the mainsheet block instead of a 2.25" block, which is standard on the newer H16s"?

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Mark J
'81 H16

I am not sure but think it is because the 40 mm blocks only come with a full-time ratchet (like the 40 mm H2612) or no ratchet (40 mm H2647), while you can get the larger ones with the on/off selectable Hexaratchet (2.25" H194) or the automatic load-sensing Ratchamatic (57mm Carbo H2629), both of which can be rigged low profile 6:1 by adding an eye to the cam arms/plate.

I am temporarily using a full-time ratchet 40 mm H2613 Carbo Ratchet w/becket (I filed off the becket and added an eye to the cam brackets) on the bottom because I got it cheap. I will likely switch to a 57 mm H2629 Carbo Ratchamatic or the non-ratcheting 40 mm H2647, because I don't like the full-time ratchet of the H2613. I am using 3/8" line.

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Alan
'86 H16, Sail #89057