Maybe someone can confirm the year(s) for a 3837161 head casting code? I cannot fine that information.
I know this thread is a bit dated, but I can confirm that my '55 235 has the same head casting number (3837161 GM1). Must be a very short run with this casting number because I cannot find it *anywhere* else. I popped off the valve cover to look at the date stamp and it is stamped J125. Correct me if I'm wrong, but I beleive this confirms the head is a '55, casting.
The head is mounted on the original 235 block with F255X stamped, indicating it is a Flint second series 1955 block for the 3100 series. It too has the J215 date code casting above the starter.
I'm glad I found this thread because there was practically no information to be found anywhere else. I can provide photos if desired.
