I stand corrected ... I read-off a spec that was high-lited in that manual.

The 440 spec for COMPRESSION RING SIDE CLEARANCE IN GROOVE is 0015 to 003.

I checked before on some NEW pistons I have ... some cast OEM-type 413 pistons and a set of forged 383 OEM-type pistons.

I could NOT put a 002 feeler gauge into either groove with a ring in place. And I also have a set of used 413 pistons .... a 002 feeler was just a tad loose.