[Dave Samson]

There must be some truth to the camshaft lift/backpressure theory because I had no exhaust problem until I installed a wilder camshaft 5.5 degrees advanced.
If you think about it, a balance (cross-over) pipe makes good sense for a "V" engine, I was frankly amazed at how it seemed to calm the lumpyness out of the camshaft.
Here in Australia our high performance production cars running GM and Ford V8's all have balance pipes installed as a standard feature. They are simply a pipe that joins the 2 exhaust pipes at the closest point of around 8 inches, usually around the middle of the car. As I run open side pipe, the closest they come together is 36" so that is the length of my balance pipe. It seems to work well and certainly allowed the fuel injection programmer to set the engine running very smoothly throughout the rev. range gaining around 30 hp. Sorry I have no pictures from under the car but you can imagine how it looks.