An early P-61 Black Widow in the Pacific War

What if the P-61 Black Widow entered service by December 1941?

Its greatest early value would be long-range night reconnaissance and interception, potentially including earlier warning of the Pearl Harbor strike force.

The R-2800 engine existed early enough to make an earlier Black Widow conceivable, but radar and night-fighting equipment would present the principal development obstacle. In the Pacific, its long range could extend reconnaissance and air cover from island bases. How quickly the aircraft reached Australia would determine whether it changed the early campaign or followed the Lightning's deployment timetable. Night patrols from Pearl Harbor might locate the approaching Japanese carriers before launch and provide several hours of warning. The same aircraft could then engage the attackers, using boom-and-zoom tactics to exploit its performance against early Japanese aircraft.