Playing practicing figuring compression ratio on a known stock 77 400 engine for fun to see how it works. I have all measurements taken except dome/dish volume on the piston. Is there a factory trusted figure I can use in Ccs or do I have to figure it out on my own? Thanks.

pretty sure they are just flat tops; no dome or dish. all you need is pin height.

Flat tops.

Oh ok. I guess I never entertained zero as the number but that makes sense. Thanks.

Just for kicks and giggles, NHRA blueprint specs for a 74/75 400-4 Are min head volume of 83.1 67cc and max deck height of - .075.
Although not currant it will give you an idea of stock specs at on time.

NHRA specs and what actually rolled off the assembly line of the Chrysler corporation are not even remotely the same.

From my own measurements of an untouched 400:

Pin height= 1.812"

Deck height= .122"

Head= 90 cc

Gasket= .022"

CR= 7.52-1