"The Mack B series is a model line of trucks produced by Mack Trucks between 1953 and 1966.  The successor to the 1940-1956 Mack L series, the B-series was a line of heavy conventional-cab trucks. Adopting a more streamlined appearance over its predecessor, the B-series was designed with a sloped windshield and larger, rounded fenders.   The model line was sold in multiple configurations, including tractors and straight/rigid trucks, cowled chassis (delivery body or bus), or fire trucks.

The B-series was the first Mack truck produced with a diesel engine, introducing the Mack-produced Thermodyne inline-6 in 1953.

During 1966, Mack replaced the B-series with the Mack R-series, which lasted into the 21st century.  In total, 126,745 examples of the B-series were produced over 13 years."