While my type of exhaust is commonly called a 180-degree crossover, my primaries cross under the the oil pan rather than over the bell housing. So I guess it’s a 180-degree crossunder. To allow the headers to be installed/removed the left and right sides will be split via flanges under the middle of the oil pan. I was unable to find anything appropriate so I designed a profile and had them CNC machined from 3/8” 304 stainless steel. To minimize the overall height the tube center-to-center spacing was increased to allow the bolt holes to move towards the middle.