Despite it having only six-cylinders, the 305E has the reputation of a big-block engine due to its large displacement. Although the 305E produced a respectable 165 horsepower, it had more reputation for its torque, producing 280 foot-pounds at only 1,600 rpm. Because of its pulling power, the 305E came exclusively in GM’s truck line from 1960 until 1966. Care should be taken not to confuse the 305E’s tune-up specifications with those of the other 305 engine types.
Note that the valve lash must be adjusted only after allowing the engine to reach normal operating temperature. The valve lash for the intake valves is 0.012 inches. The valve lash for the exhaust valves is 0.018 inches.