Dude, you're either grasping at straws or you really don't understand the mechanics behind the PCV. AFAIK there isn't a positive pressure coming from the combusion chamber input where the PCV attaches so the breather will have the same effect as the crossover tube with or without the catch can. That said, I haven't measured it ... & I've proven myself to be fallible so please feel free to enlighten us less informed as to your logic.