From Dan Whitney, op.cit. - words between [ ] are mine :
(page 269) F-11R : This engine was intended for the Curtiss P-53 airplane [a P-40 improvement, drawn after the XP-46 failure], and represented an effort to dramatically improve the efficiency of the Allison-designed [single] engine-stage supercharger then being used on all V-1710s. The V-1710-57 (F11R) was the first to use a two-speed supercharger, having th ability to shift between 6,44:1 and 8,80:1 drives. Contract ... was issued for one of these engines in October 1941, the engine was to be delivered the following March... The model test engine ... was actually completed on April,2,1942, and was unusual [carburetor change]... Particularly unique was the supercharger impeller, wich was an entirely new "lixed-flow" unit known as the "Birmann" supercharger... The impeller was of 10 1/4 inches in diameter and involved aspects of both centrifugal and axial flow in its design. The engine was otherwise similar to the F-10 ... Evidently the improvements shown were marginal and did not justify introduction into production at the time.
(page 280) G-3R : eight of these engines, were military versions of the proposed commercial G-2 model [a F-30 with a new two-speed supercharger], were built as V-1710-131 to power the Douglas XC-114 (a C54E derivative with lengthened fuselage) and YC-116 (similar but with thermal de-icing). Both were contempraries of the DC-4M "Merlinized" C-54..... The first engine went to test in December 1946.