Don't know if anyone reads this thread anymore, but thought I'd post this anyways. I need to run a Cline regulator on my 1.80, so I wanted to get it set up on the test stand befor going into the plane.
about 47 degrees F
wildcat 15%, 18%synth/castor blend
MA Classic 18x6
Cline regulator

8800 rpm
idled as low as 1350-1400 rpm, no heat (sounded like it wanted to stall, but ran for a full minute befor I turned it up to a smooth
1800 rpm idle. Idled at 1800 for 2 minutes, smack the throttle wide open, not a problem...8800 rpm.

It really likes the steady fuel pressure with the regulator.