Thanks Apophenia,
Used your suggestion on the name.
At the end of 1942 the NA company came with the FJ-2 with an in-line engine (they were already testing the P-51), but the Navy tested the plane but rejected at last. So NA approached again the USAAF with this upgraded P-64 as the P-64C and the USAAF were satisfied and ordered 100 P-64C's. Here is one from the Aleutians:
NA tried again to satisfy the Navy and send the F3J-1, an upgraded F2J-1 with an in-line engine. It was tested and the pilots were really fond of the machine. Here is one from VF-51.
friendly regards
Lauhof