240DieselDog

You can tell the difference because the towers are constructed slightly different. The new (Hard) style is SLOPED on one side below the round part that holds the cam and with the old style the tower is VIRTUAL below the bearing. The acorns are LESS tapered in the new version (tapered from hex to round on top) and you can see the "layers" in the rocker face of the new style. The place I go to for used parts just has a bunch of engines sitting around in a dark room (bring your own light) and it can be hard to tell the differance.

Steve