From info that I pulled from"R-2800 Pratt & Whitney's Dependable Masterpiece" by Graham White The highest "Military HP" rated engine used in the F8F was the R-2800 -30W which was rated at 2250, these numbers being supplied by P&W. Not sure if the "Military" rating is the equivalent of W.E.P. Of note on page 228 of this book the author states: "it may be noted that some of the military ratings appear to be low compared to previously published figures. As an example, R-2800s powering P-47 Thunderbolts are often quoted as developing 2800 horsepower. This may have been true: however, to generate this much power, the recommended manifold pressure is exceeded. And in the heat of combat it can be safely assumed that this is what occurred. For engines with automatic boost controls, it was not unusual for crew chiefs to "tweak" its adjustment to allow greater than recommended manifold pressure."
Hope this helps