most obvious external difference is the engine valve covers. The 351W
(Windsor) valve covers are attached with 6 bolts, straight front to
rear, and narrow in width (similar to the 302 c.i. engine.)*
The 351C (Cleveland) valve covers are attached with 8 bolts, flat
with 2 different planes, and wider in width.
The 351W engine has a radiator hose that attaches to the intake
manifold, while the 351C attaches to the engine block. (See Graphic 1).
The 351W takes a 5/8” thread spark plug and the 351C takes a 14mm
thread plug. (See Graphic 2).
The 351W has a smaller 1.245” diameter distributor gear, and the 351C has a larger 1.418” diameter distributor gear.
Each engine has a 5/16” oil drive at the bottom of the shaft and a
1.557” diameter housing, measuring directly above or below the O-ring
Note: * The Ford 302 c.i.
engine has a 1/4” oil drive on the shaft, a small 1.245” diameter gear,
and a smaller 1.550” diameter housing.
Windsor 351 V8 Engine:
- Valve cover is held in place by 6 bolts.
- Radiator hose connects to water neck on the front of the intake manifold.
The 351 Cleveland’s radiator hose attaches to the radiator and
connects directly into the front of the engine block. It makes a 90°
bend from the radiator to the engine block.