Rod length versus piston compression height

It depends, most 4" stroker pistons are for a stock length 6.123" rod and adjust the pin height in the piston. On my 408 I ran a Chevy sized rod 6.125" long, 2.1" rod journal with a .927" pin. I ordered my crank with the 2.1" rod journal because it opens up more options for rods and bearings. My new build uses a 4.125" crank with 2.00" rod journals and a 6.200" rod, obviously the pin is closer to the top of the piston than a 4" stroke piston.