I am not to savy on these particular pistions but do not like the chamfer if you are wanting to use nitrous a lot. Nitrous is like a "blower in a bottle" and having a "weak" upper ring land is not what you want. For nitro and nitrous I went extra thickness on the top, once to 3/8" and another time 5/16" above the top ring. I even use .220" on high compression gasoline. I personally have never seen this much chamfer; hopefully some one here will respond with an explanation..Good Luck
