I certainly don't recall using 25/25 for a 120KIAS navex.
2600 rpm / best power mixture / induction air cold, whatever MAP it took and to hell with the fuel consumption!
When we took a 10-ship from RAF Abingdon to RAF St Mawgan, everyone else used the normal 2400 / 19" cruise. I pulled the RPM back, pushed the MAP up to 'parallel needles' and leaned the mixture as far as I dared.....saving at least 3 gallons in the process. But we'd stopped teaching the use of anything less than 2400 rpm by then - and I gather that a few years later 2600 rpm actually became the norm.