Different data isn't necessarily wrong, especially for an engine built in very limited quantities without much information.
US Navy Figures
1941, to be manufactured by Ford
Two stage , four speed supercharging. 100 octane fuel
max.about 2,600hp at SL,
3000rpm 36,000ft, 1,950hp
3000rpm 45,000ft, 1,150hp
Bore 5.25in stroke 6in
Compression ratio 6.0 to 1
Dry weight 2,140 lbs ( lots of different figures, 1860lb dry weight in 1938)
Propellers 570lb contra rotating