Okay, if you look close at the pic, you can see used a 1/2" diamater x 1" long extension piece of copper pipe and a copper elbow. The straight 1" piece is not just part of a copper pipe I cut, it is a fitting that I bought because it's meant to fit tightly around a 1/2" pipe. Since it was designed to fit tightly around a 1/2" pipe, it fits very tightly on the copper elbow, so tight that I had to hammer it on a bit. But before putting the elbow on, I jammed the extension piece onto the original header. The header is also about 1/2" in diameter, so it wouldn't fit. I had to file it around the outside quite a bit to get the copper extension to get on there, then I had to hammer it on the end a bit to get it to go on. It all fits so tightly that it supports the muffler on it's own, but the chassis also supports the muffler at the other end. I just got all these pieces to fit together very tight so they don't move around at all. I didn't know it was going to be like this, but as a bonus I didn't have to sodder the pieces together. I was planning to, but it wasn't required. I didn't cut the original manifold though, I just added to it, but I'm thinking of cutting my manifold so I can move the pipe to the side of the car, but I can't see why it wouldn't work to cut the manifold and add a piece to where you need it. But just to be safe, it I was going to buy a special tuned pipe, if I had to modify my manifold to get it to fit, I would try to keep it's total length pretty close to the original total length.