PowerPipe Exhaust for slant/6

can you explain to us how the design is in any way beneficial? Not to attack but from the look of the design I cannot see how this would flow well at all. Can you do a 3 way Comparison this unit on a dyno with the same morot on a dyno with a stock manifold and a competitors (such as a dutra) I am just not getting this.

That's 'cause there's nothing to get, except a bunch of handwaving and BS. See here and threads linked from there.