Centaurus:
Just at the moment I can't lay my hands on the SB I'm thinking of. Based on memory, it recommended mixture above 2000ft and smooth closure of throttle at lower levels. I thought the reason for preferring mixture was piston slap (caused by reduced pressure above the piston when throttle closed at high RPM) but it may well be that my memory has failed me and that the primary nasty was detuning of the balance weights. There's a more detailed discussion of the counterweight issue in SB245, but this specific SB does not cover IO360s, etc.
When I track down the one I'm thinking of I'll post the relevant text (unless I dreamt it).
HFD