I've always been told that the 848 head was the stock head on a 235 from 58-62. But, they were also sold as replacement heads. I'd be inclined to think that an 848 head on a 54 235 could or would be a replacement head. I don't think I would be looking at 54 235's for an 848 head, but instead I would look at the 58-62 models.
Joe
