per Cap'n Bob... >>Early P-51s had Allisons >>Later (Most) had the Merlins Interestingly, some late P-40s also had Merlins! :-) I remember many years ago, in the ads in the back of Autoweek, seeing a matched pair of counter-rotating Allisons, for a P-38, advertised New In Box for $25,000. :-) Ed in NC