[dtw]

Did you ever relieve all torque on the tower and try to turn the cam? At this point, I'd pull the cam tower off the engine and test it on the workbench. See my prior notes though, binding cams are frequently an indicator of an uneven deck. This can be an issue with the case, cylinders, heads, or all of the above. If the cam turns freely on the bench, you have issues with another component(s). Relieving the tower journal won't fix that.