From this week's AvWeek. Boeing responded to an Air Force RFI against a
requirement for improved bombers by suggesting re-engining the B-1 fleet
with F-119 engines with the following characteristics: Mach 2 cruise, 3000
mile radius, 60,000 foot ceiling (with a couple of hours loiter).

Is this plausible? From others in this group, I though the B-1 was marginal
above 30,000 feet.