Identification Help

There should be numbers cast into the side of the block. It sounds like you found the stamped numbers on a machined flat at the front of the engine. I think the relevant numbers are on the driver's side. Usually it has a "-318-", "-340-" or "-360-" in the characters, though the dashes are more like wide dots. The earliest LA engines, 273 cu in, did not have "273" in the string (I have 2).

There were at least 4 versions of timing cover (see my post). Most earlier engines (pre-1971?) with the cast iron water pump and inlet on the driver's side had a removable sheet-metal timing marker. Indeed, somebody is looking for one in today's posts. Later alum water pump models had the timing marks cast into the driver's side of the timing cover. However, I ran across a timing cover with cast passenger-side timing marks (see my post).