Tapping your original Manifold will not work it is too thin and does not have enough to thread the presure fitting on to. Same goes for the muffler.
Trust me guys I have tried this many times many ways. It might work for a couple of flights and then it will become loose and leak. I have even tried with JB weld same effect works only a short time.
Try it on your own just in case some one does not belive me.
Thanks guys,
Eddie