The twin Allison engines performed admirably in the Pacific.
This was primarily due to severe shortage of spares for the Allison engines.
Consequently, on 31 October 1941, a contract for 1,950 P-60A fighters using the Allison engine, was awarded.
Even the Allison engine was removed and used to power a hydroplane racer.
With the original Allison engine - long since removed, the replacement powerplant was no more than adequate.
There is no evidence that the XP-82A was ever actually flown, due to problems with the Allison engines.
They also had difficulty with the more demanding requirements for fuel quality and oil purity of the Allison engines.
The distinctive chin airscoop grew larger so they could adequately cool the large Allison engine.
Allison engines were also considered to be more badly needed for constructing fighter aircraft.
This deficiency was due largely to the single-stage supercharged Allison engine, which lacked power at higher altitudes.