What is the modification that needs to be done to make them work... anyone know?

 

The inside of the valve covers have metal supports that hold the bolt "tubes" in place. The Pro Magnum RR's have very little clearance between them on the top half of the head, therefore the metal support interferes. The supports between the tube and the top side of the valve covers needs to be removed. The lower side supports can remain in place.

 

There are some good pics at the bottom of this page.

 

You guys are friggin awsome...