The third line clamps to the other 2 with S hooks. Mine fit like a glove on this car all the way to the front.

My black 74 has 3 lines also just like this one and is how they ran them on hemi and 440/6 cars.



You ask for a 1970 hemi cuda return line, stock size is 1/4" OD which I think is plenty large enough for most cases. But if you wanted a different size I am 90% sure they could bend it up in a larger size too. Fine lines could provide new hardware too. Not exactly stock but plenty close enough for me and a street driver. They had the hard to find hardware for fuel line mounting.