This is the start of my list. Feel free to add to it.
1937 First 216, Dome pistons. Four bolt flywheel. Head straight along manifold side.
1938
1939
1940 First rear main seal. Three screw oil distributor. Six 3/8” flywheel bolts.
1941 Scalloped around head bolts on the manifold side. Flat top pistons. First truck 235, has raised 235 on oil pan below distributor.
1942 Six 7/16” flywheel bolts
1943 War years
1944 War years
1945 War years
1946
1947
1948 Narrower rod and main bearings. 48 inside 2” circle between distributor and draft tube.
1949 48 inside 2” circle between distributor and draft tube. Exhaust manifold angles back.
1950 216 has a 2” circle buy its self between distributor and draft tube. First passenger 235, (smooth contour between spark plugs), short side cover. 2” circle with a small 0 in the center, between distributor and draft tube. Power glide engine only has front throttle pivot.
1951
1952 First side mounts, three bolt pattern (two bolts on top and one at the bottom).
1953 First year full pressure 235 with insert rods and aluminum pistons, used in Power Glide cars, stick cars use splash 235 with cast iron pistons. All 235s used the same head, (scalloped between spark plugs). Pass with P.G. uses rear throttle pivot, front is not drilled or threaded.
1954 Change over mid year for cam from forged to cast. Four bolt valve cover, only year with four vent slots.
1955 Change over mid year for main bearings from dowel top and bottom to dowel top and tang bottom. Front side mounts.
1956 First electric temp sender.
1957
1958 Rocker receives oil through cast in oil galley. All are drilled for hydraulic lifters. Three bolt center side mounts, (one bolt on top and two on the bottom).
1959 Rocker supply orifice increased from 1/16” to 11/32”. Rockers have oil groove offset ¼”. Valve cover fill moved to the center.
1960 Dropped front throttle pivot. No front side mounts.
1961
1962
