2 piston dsm brakes vs the n/a, 3/s, 2 piston brakes

[viridionplague]

i knew they were different, i just could find anything or anyone that could tell me the actual difference. i tried many searches. compared alot of parts on napa's website ... ect ect.

but if its only 1mm i wont bother switching to the 3/s calipers then. there was a couple sets in my local junkyard so i thought i would ask about them.