The first year for the non-Springer front end and the second year for the Panhead engine which replaced the Knucklehead. This one is an FL which means that it is a 74 cid. (EL's are 61 cid.)
Note that the frame is still a hardtail frame. The hardtail frame was replaced in 1958 with the Duo-Glides. At that point, the motorcycles had shocks on both the front and rear.
The motorcycle is a tank-shift (hand shift) 4-speed with a foot clutch.
This motorcycle is at Uke’s Harley-Davidson in Kenosha, Wisc.