Dipshit Fuel Line Question
I had the same situation, going with a carb on the 69 Dart and I wanted a vapor return line. I got the pre-bent 5/16" line from In Line Tube (great folks, BTW). There were way too many intricate bends for me to feel like messing with making my own, and the price was quite reasonable. I got a roll of 1/4" for the return line and bent that to roughly match the supply line. I drilled a hole in the t-bar crossmember to pass it through, and then just zip tied the return line to the supply line.
I still have the old factory supply line if you want it to see if it is the same as your 64.