Can anyone recommend a book that tells the story of US bomber crews over Korea?
I imagine it must have been a totally different experience compared to flying B-29's over Japan in '45, what with all the Migs.
Most of the books which cover the air war over Korea include a fair bit about the B-29 actions. Osprey's B-29 Units during the Korean War is a good place to start as well.
The B-29 was effectively obsolete with the advent of jet fighter opposition and they did suffer a mauling by the MiGs, the major reason why daylight B-29 bombing missions were halted. MiGs with their cannon armament and especially the 37mm were very good bomber destroyers. The Soviets had carried out testing with an interned B-29 and ascertained that it usually only took 2 hits with the N-37D's 0.75kg HE shells to knock a B-29 out of action.
Black Tuesday Over Namsi by Earl J. McGill
A very detailed account of the epic air battle that occurred on October 23, 1951 when nine B-29s on a mission to bomb Namsi airfield were engaged by Soviet-manned MiGs in which six of the nine B-29s were shot down.