PaperTiger is quite correct when he quotes the R-4360-20 being installed in the C-119.
Also fitted were -20WA's in the C-119C.
For Lu, there is a PDF file in the AHES site under P & W and search through R-4360, which lists all the various dash# and applications for R-4360
The Fisher a/c mentioned, the XP-75, utilised the so-called double Allison-V-3420-19 installed a la P39, P-63 behind the pilot and driving the propellor via a long extension shaft.
8 XP-75's ff 30-9-43, plus 5 P-75A's built.
The P-47 on steroids was the XP-72 fitted with an R-4360-13, 2 of which were built, ff 2-2-44.
Quotations from :United States Military Aircraft since 1909, by Gordon Swanborough & Peter M Bowers. Published by Putnam.
New Edition 1989
ISBN 0 85177 816 X
To clarify the Lycoming XR-7755-3.
This is a size in cubic inches, and not a horse power figure.
Excellent references to be found at :
AHES
Regards,
HectorusRex