Well I played around with the F6F last night and am pleasantly surprised with the new flight models. I took off and climbed to 25,000ft using the settings in the Checklist. Now bear in mind that I derived these from the original real life F6F-5 flight manual.
At 25k the plane was within 5 KTAS of the published airspeed. The power settings from stage 3 blower (real life setting of high) could not get to the published power of 49.5