Roller rocker question?

Not sure about the groove thing. Did you install your 1.6 pedestal mount rockers? If so, did you use shims to get the proper adjustment. That's what I had to do back when I put 1.72 rockers on my old motor, which was stock with all the bolt ons.

In my experience...roller rockers should last well past 40K miles.

As for noticing a difference with the 1.7 rockers...they'll give you more lift. You may feel it. You'd probably have to hit the 1,320' to find out for sure. But every little bit helps, right?