Actually all Bearcats had single stage engines and had combat ceilings (Navy minimum 500fpm climb) of 35000' and service ceilings over 40000'. Excellent high altitude performance. Resulted from weighing 10000# instead of 13500#.
as noted there was a considerable difference between the 1941-42 R-2800 single stage engines (B-26 bomber and Lockheed Ventura) and the engine
s used in the Bearcat.
The -5 engine used in the early B-26s had 1850hp for take-off and 1850hp Military power at a whopping nosebleed altitude of 2700ft. yes 2700ft not a typo, in low gear and 1500hp at 14,000ft in high gear. This was the R-2800 A series engine. The B-series single stage two speed engine (the P-47 used a single speed single stage supercharger in combination with the turbo). most two speed B engines were rated at 1600hp at 13,500ft in high gear and that 2000hp for take could be held to 1500ft, yep again, 1500ft.
In addition to the weight "cut" (in part because the F8F-1 carried 1/2 the guns with less ammo per gun and a bit over 1/2 the fuel)
The Bearcat used 3 different engines
the R-2800-22 with 2100hp for take-off, 2100hp at 1000ft and 1600hp at 16,000ft. (XF8F-1)
the R-2800-34 with 2100hp for take-off, 2100hp at 3000ft and 1700hp at 16,000ft. (F8F-1, and a few prototypes)
the R-2800-32 with 2250-2300hp for take-off, and 1600hp at
22,000ft. (F8F-2). Please note the -32 engine used a variable speed drive and not a two speed drive in addition to other improvements. Also note that the "C" series engines offered better cooling and needed either 10% less airflow through the cowl and engine baffles for the same power or could make more power and still hold temperature in chick using the same airflow as the B series. This mean slower drag at the same power outputs.