A '70 440HP piston should be .090" in the hole (same as the '67), '68 and '69 should be .050" down.

'70 was the first compression reduction for the 440-4, they went from 10.1-1 advertised to 9.7-1 advertised; they used the shorter '67 closed chamber pistons with the open chamber 906 heads to reduce the compression.

The TRW 2266 piston is the same 1.991" compression height as the original factory '67 and '70-'71.