This advice may be hard to stomach, having just had the expense of an new engine, but have you considered fitting a fuel flow meter before you start the engine break-in?
A fuel flow meter pays for itself very quickly, even without considering what it might save you by avoiding glazing the cylinders.
The well known avionics retailer in Edinburgh is selling the excellent JPI FS 450 for £425 incl VAT.
I'm just reached 8 hours on my rebuilt engine (O-320), although on my aircraft the extra fuel flow of operating at 75%+ power doesn't seem to produce much extra speed, just extra RPM! (I have a JPI FS 450 and would not be without it!)
Good luck with the break-in.
tp