[JSeery]

Some hints would be the "pencil test". If you were to place a pencil above the front timing cover is there a ledge it could rest on (32-42)? The shape of the holes in the center of the block between the cylinders can provide information. Lots of little hints. If it was a 41 it should have no freeze plugs in oil pan rail, intake area now looks raised. If it is 24 stud and not a 41 then that would narrow it down to late 38 to 40. There was a main bearing size change around 39.