There are lots of ICON pistons available for the 4" stroke crank with a compression height of 1.445" in most variations except for the dome pistons that come with a 1.465", but they are all made with the .984" pins. Using a 1.445" compression height piston would be great with a 6.250" rod IF you could get them in a .984" pin, but you can't. I know JE makes a shelf piston for a 4" stroke with a 6.125" rod length and .927" pins, but they are over $1500 a set.
Tom