The first variant developed in the 737 MAX series, the MAX 8 will replace the 737-800 with a longer fuselage than the MAX 7. Boeing plans to improve its range from 3,515 nmi (4,045 mi; 6,510 km) to 3,610 nmi (4,150 mi; 6,690 km) after 2021.[50] On July 23, 2013, Boeing completed the firm configuration for the 737 MAX 8.