Complex sentence: At its peak in 1944, the Willow Run plant produced 650 B-24s per month, and by 1945 Ford was completing each B-24 in eighteen hours, with one rolling off the assembly line every 58 minutes.
Split into simpler sentences: At its peak, the Willow Run plant produced 650 B-24s per month in 1944. By 1945, Ford was making a B-24 in eighteen hours, with one rolling off the assembly line every 58 minutes.