Anyone know the typical difference in speed between onset of buffet and full stall in a 360?

I am reluctant to fully stall my 360 to get the stall speeds for AOA calibration. I have taken my plane to the onset of buffet, and I get 61 KIAS with the flaps down and 66 KIAS clean. I have calibrated my AOA instrument with these numbers, but I think these speeds are a few knots too high.

The Sport Aviation article of a couple years back which reported on the performance of Fred Baron's 320 says that his buffet occurs about 5 MPH before stall. Can anyone else give me stall speed and buffet-onset speeds for other 320/360s.  Thanks.

Mike Reinath
Std. Build 360 MKII (60 hours flown)
N3602M