These headers are for classic mustang and cougar 67-70. These are made specifically for these cars and thier tight shock towers. These will fit 289 and 302. 351w if you wanted to cut some shock tower. But I will be making a set for 351 hopfully in the next 6 months or so. This auction is for only the headers. After the auction you can buy the crossover and down pipe if you would like. The headers are made of mild steel. the flanges are .500 in, and the tubing and collectors are 16 guage (.063) thick. The flanges are V-bands, so no paper gaskets to blow or leak. these are quility headers. But I made a mistake on the assembly. the collector was rotated the wrong direction. So the one primary is dinged to fit. these still fit the crossover fine. But the headers will not go this cheap again becasuse the jigs are correct now. They are priced a little over what they cost me to make. They have a little surface rust on them and will be cleaned before shipping. All welds are tigged. Since there isn't must room, you will need a oil filter relocation kit that can be bought at Summit pretty cheap. And you cannot run P/S, A/C or a sway bar. But belive me the boost from a turbo is worth any sacrifice. In single turbo apps, there will need to be a hole cut in the fender apron for cold air. Good luck and ask any Q's. You can find pics on ebay under classic mustang turbo headers on ebay.