Which one is better? (long)

Let me throw another thing out here for discussion. My 71 dart has a nipple above the sending unit. I stripped out a 70 318 car that also has a bad gas tank. That fuel tank DOES NOT have a nipple above the sending unit. It has a nipple on the filler neck, very close to where the neck is screwed to the quarter panel. Also the filler neck on the 71, without the nipple is approx 3-4 inches longer than the 70 filler neck. Look up in factory parts book only says w/wo ecs. What am i missing here? I have a 71 fsm but not a 70.