Several years ago, I used a product Hedman called "weld rings" or "spring rings" to fab the headers for my Willys. These things were (I think) stainless, they had a "springy" aspect to them that when compressed, they would fit INSIDE the tubing. They had a raised lip that kept the ends of the tubing at a weld perfect separation, (.020?) and a "lip" (maybe a 1/16") that extended into the tube. Well, I'm fabbing another set of headers, my leftovers are used up, and I can't locate them anywhere. I'm afraid Hedman discontinued them........anyone have any they would be willing to sell off, or another source for them other than Hedman? I'm working with 1 7/8" OD tubing. Any help appreciated.