Was the cam tower milled to compensate for a reground camshaft? I ran into a situation with my engine where the cam tower was not the stock height due to a previous owner milling it. I milled it again to compensate for a regrind and it held my valves open after assembly. I ended up shimming the cam tower to the point in which the compression came back up on all cylinders. Have you ran a compression check yet? What is your cold cranking compression on ech cylinder? You should do this to determine which cylinders have compression or if any do.
