The 848 head is listed in MPC, dated, effective, April 1, 1956.
Listed in 1956 catalog and also 1959 catalog as
Casting # 3836848
Part # 3730415
It is also listed in the Passenger catalog 1938-64,
with a different Part #.
Casting # 3836848
Part # 3836954
Online I have seen a 848, GM 7, date code A266.
