I built a mousse can muffler & was wondering about attaching it to my Macs Header, should I cut the header or leave it the stock length? I plan on installing it on my OS .46FX with a 11/6 prop. An article from Macs said to cut the header to 3.375" for my engine but I don't know if that is for one of there tuned pipes or if it's the same for the mousse can. Thanks