Just a thought on this.
Check that the cam cover vent pipes are on the correct stubs. There are 2 sizes of breather, one large and one tiny. You can't tell which is which without looking at the inside of the cam cover or probing with a small dowel. If the largest outlet is going to the manifold, this would cause the revving you are getting. The larger output should go to the throttle body. The outlet with the tiny hole must go to the manifold