To my knowledge, they were still building them as bypass engines for applications other than heavy truck. It was an option in 3/4 and 1 ton pickups in '62, and I've been told that some '63 1/2 and 3/4 ton 4x4s also used them. However, the casting number for that block points to it being a high water pump block. That would lead me to believe it's a replacement block for a '54 or '55 1rst with the bypass filters system used for that year range.
