Theoretically it could be a 58 block by the casting number but that number ran from 58-62 so really it could be from any of those years. But we can narrow it down even further by the casting date of D 17 1, which is April 17, 1961. So it appears you have a 61 235 block.
Thanks Mike! That makes a lot more sense that the 1 would refer to 61. I appreciate the help. My grandfather had the truck for close to 50 years before he passed and I inherited it. He had always told me it was a 54 engine but I don't see any way it could be a 54. It seems to me based on the numbers that it was cast in Flint, MI on April 17th, 1961.
Any benefits to having a 61 235 over an earlier model?
