Original Harley-Davidson heads

Cstg. No.

Use

Interior
fins*

Exterior
fins

Intake ports

Oil feed

Manifold

Pictures, click for a larger view

119 48

1948

3

Small

Threaded
male inserts,
180° apart

Internal

“T”

119 49

1949

119 50

1950-54

706-55

1955

O-ring lips,
180° apart

706-56

Early 1956

16700-56

1956-57

4

1958-62

Large

Late 1962

**

1963-65

External

* between the valve guides, only visible inside the cover
** has the external boss on the right side of both heads for the external oil line, but it’s not used     With the D-ring facing you, and the spark plug thread on the opposite side:
    The front head will always have the exhaust port on the right, the intake port on the left.
    The rear head will always have the exhaust port on the left, the intake port on the right.
    The exhaust pushrod hole will always be slightly closer to the edge of the D-ring than the intake pushrod hole.
    The oil feed holes will always be on the pushrod (cam) side; the oil drain holes will always be on the spark plug (drive) side.
    All heads have their casting number or part number, ending in the 1st year of use, cast into the D-ring flat surface:
    1948-55 heads have their casting number on the lower surface of the D-ring (visible from below, even on an assembled engine).
    1956 heads were made both ways (despite Palmer’s comment). Early 1956 heads have the number cast into the bottom of the D-ring ledge (visible from outside) and are based on the 1955 (3 fin) O-ring casting.
    Later 1956-65 heads have the number cast into the top of the D-ring ledge (inside the cover, and invisible when assembled) and begin the 4 fin type.

STD heads

    These were made for all years, with the shovelhead (angled) ports to accept the 1957-77 Sportster/1966-77 shovelhead 120° “Y” manifold and 3-bolt shovelhead style exhaust flange.

S&S converted Harley-Davidson heads

    The S&S dual carburetor panhead conversion was a cast aluminum block that replaced a huge chunk of the original intake port area, apparently the default was a Linkert 1½” 4-bolt (M-74B, etc.) flange. Note than the bolt pattern is rotated 22.5° (half of the H-D 45° “V” angle) so that the Linkert is “normal” when the heads are actually mounted to the engine. The port diameter appears to be the original 1.56”.

Unknown converted Harley-Davidson heads

See these Victory Library booklets