When I was flying behind a Sensenich, ground idle was between 700-750 rpm and final approach idle maybe 1050-1100. This on an IO360. Of course you can adjust the ground idle and approach idle will depend on your approach speed and angle.
Normally around 700 after runup but after flying today, just before shutdown it was 650 RPM. It really seems to vary a lot with temperature. In cold weather I've seen it as high as 850 RPM. It's a mystery...Snopercod, what is your warm ground idle speed?