I have a 60-61 235 6 cyl block with part of the valve train missing. Is there any way to tell if the cam is mechanical or Hyd. It's still there but I can't see any numbers. Also any way to tell what the original lifters would be and the length of the push rods? I tried several old car manual project manuals and can't find any definitive information without part numbers. If I decide to replace the cam/lifters how do I tell if the block is okay for a hydraulic cam.