.

Casting #CIDYearID CodeCC'sNotes

.

383821400-42565A80Unique 3/8" stud and nut rocker mounting, using a 3-piece rocker pivot assembly; all except irrigation

.

383821400-42565'B80Later '65 heads. Some use 3-piece rocker pivot assembly.

.

389395400-42566'B80Toro's and 442's got the big 2.072 valves. Some use 3-piece rocker pivot assembly, -1 after the casting number on all B heads after April 21, 1966.

.

394548425-45567'-69'C80A/C '68 H/O's. Toro's and 442's got big valves. Rumored to flow the best of all BB heads. Can still be found. Very small 3/8" ID lettering.

.

40037040068'-69'D69.75All W-30. Non A/C '68 H/O's. All '69 H/O's.

.

40037045568'-69'DA69.75All big-valve.

.

40368645570'E77, 80455's in general, with 442/Toro's having big valves.

.

40443845570'F80W-30's. All big-valve units.

.

40910045571'G80Generic 455 use, big valves in the usual applications.

.

40910045572'GA80W-30's, manual 442's used big valves.

.

40916045571'H80W-30's. Big Valve units.

.

41178345573'-76'J80, 82All 445's. 'Smog heads' restrictive exhaust valve pockets. No big valve units.

.

41319145580'K80K and Ka heads were not factory installed in production cars.

.

41319145573'-76'KA80Marine, irrigation, industrial, W-30/Toro, 42 4-speed replacement head. Most were big valve units.K and Ka heads were not factory installed in production cars.