I need to make one correction on my previous P-39 post: The P-39 gearbox appears to be an
internal spur gear type. Thus with the prop turning right-hand, the engine also turns right.
And I've found several web references to the RH <> LH conversion of the V-1710, all saying that the CRANKSHAFT (not camshafts) was swapped end-for-end. This is at odds with earlier information I had. For me, the subject is still open; If someone can find the V-1710 T.O. online, that would settle the matter.