Here's your engine code break down...since there is no serial number shown that make it a 1957 or newer engine.
F616K
F = Flint engine plant
6 = Month (June)
16 = Day
K = Type Designation (K for 1957 = 261 from a 6000 Series truck, K for 1958 and '59 = 235 from a 3400, 3500 or 3700 Forward Control/Double Duty Chassis, K for 1960-62 = 235 from a P20/P30)
Need the cast date code from the passenger side of the engine to confirm the year.
Mike B
