Runs at FAST idle, not slow

There is a way to set the lash without it running. Just set it 0.002" greater. You have to rotate the engine by hand. and check for maximum lash. You can use ignition rotor to get an idea of rotation position. If you have worked with old VW engines it is the same idea. Here is a method: http://www.allpar.com/mopar/valve-adjustment.html