[DeTomaso] Techno question: 4/7 Swap Cams for 351Cs

[Charles Engles]

Dear Forum,

       I just learned of something called a "4/7 Swap Cam".   It requires swapping the no. 4 and no. 7 sparkplug wires.  It is appearently the trick cam for Chevy dirt track racers and allegedly decreases "bad" reasonances and torque and karma for the crankshaft.  The Isky and Crane websites mention an eight to twelve HP gain and smoother torque curve.   The Crane website alleges that the trick has been around for twenty years.
       Anyone familiar with the "4/7 Swap Cam"?     How is it supposed to provide such benefits?     Does it work with the Ford Cleveland or is the Ford firing order different and therefore incompatible with the 4/7 Swap Cam?

                Curious, Chuck Engles