Sorry, misread you’re post.
Original P-51 (and A-36) engines were Allisons. Then RR Merlins, which were license produced by Packard.
The original RRs were certainly gone by Korea, with the planes powered by the Packard versions.
Sheesh, trying to get this right here.
The Alisons were definitely gone, never powered the P-51D to begin with.
The limited number of RR Merlins that were bought (not sure if any of these powered production P-51s) were certainly gone too, leaving the Packards.
Oh geeesh, I messed up. Sorry. I forgot originals were Allison.