KB243 Hyper Piston Confusion

PRH said

Seems like some of the confusion stems from the “flat top” description…….and the C/H being listed as “1.840”.
If the portion of the piston sitting below the deck .012” is .030” lower than the top of the piston, it would measure 1.810” to the pin C/L.

On a stock 9.600” block, 1.84” C/H ends up sticking out .018”.

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You would certainly know better than me, I'm no engine builder.

The 243's are supposed to be for the factory "10:1" 340's that originally had the pistons .018" over the deck from the factory. At least by the spec, anyway. So the later smog 340's with lower factory compression are supposed to use a different piston. I'm not really sure why the 243's are listed as flat tops, or why the rest of the published specs don't line up with the way that you actually need to do some of the calculations if you were going to actually treat it like a flat top. But that mismatch in description and actual specs/measurements has been around for a long time.