I am replacing my fuel tank, sending unit and lines. 1969 Dart, base, auto tranny, 273 cid. Does it matter if I go with 3/8 or 5/16 and does anyone know what the factory size might have been? 2 bbl carter carb.
Slantsixdan has some good posts if you search related topics. I ended up going 3/8 myself on 69 Dart 360. Fine Lines was awesome to deal with in regards to pre-bent fuel lines and clamps.
More than likely it's 5/16. 3/8 will work, but you will find the line a little tight to get the line on. I recently replaced my sender with a 3/8 becuase I intend to size up to 3/8 line all the way to the engine compartment. I am currently running the 3/8 sender with 5/16 line.