The 1957 Chevrolet Master Parts catalog indicates that the 848 head unit was sold (for $47) as the replacement head for 53-57 235s, which includes the 18-bolt 235s. The catalog shows a different part number for the replacement head for a 53-55 Corvette six, but does not give a casting number. The catalog also does not give a casting number for the replacement head for a 261.
By the way, a knowledgeable acquaintance has told me that he has cc-ed the combustion chambers of an 848 head and a non-848 head from a 235 and they measured about the same, with the 848 head actually being slightly larger. Does anyone have any different information?
Hoyt
