Denny,
No, I am not sure of the years for the 848 head. The information that I have on head codes has come from a variety of charts available on the Internet
(that Warren Foster & I compiled on this web page) .
An 848 head (as a replacement) might be found (now) on any 1954-1962 235 or 261 engine (coolant holes should have been drilled in the head, if installed on a 261). I think they were originally installed on 56-62 235s for trucks and passenger cars - I do not have a factory document to support this assumption.
I have a 1954 235 that I purchased a few years ago - it has an 848 head and I assume that it is a replacement head.
I do not know if there is a date casting on 235 heads (as there is on a 235 block) - maybe someone will post information on this.
Tim
