Bill is correct if the block is still the original. The HP352 came in two flavors with EDC-B and EDC-C as the solid lifter blocks. It's possible the block has been replaced with a service replacement at some point in it's life as they were hyd lifter blocks or has been converted to run hyd lifters. It could also be a later post 70's service block as they had no casting numbers but a date code. Does the block have vertical ribs on the outside down by the skirt? Also can you see a DIF or MCC logo cast in the block anywhere? Just looking for a few focal points to help out. Ford was pretty good back in the early 60's with casting numbers. That's why I'm thinking service block possibly. Also what numbers or digits are on the crank and rods? G.