I swapped the gas tank on my '78 Chevy last weekend (new tank, new sending unit). I have been trying to get it to start, but haven't had any luck. I primed the carb with some gas and put some in the tank, and it started right up. However, if I hit the gas pedal it would die. If I didn't hit it, it would just idle really rough and eventually die. I have tried using starter fluid as well, but it just runs for a second and dies. Obviously it isn't getting any gas from the tank. Do I just have to do this for a while until the gas makes its way through all the lines? Should it have made it by now? The only other thing I can think of is I may have crossed the fuel lines. My sending unit has two outlets (one uses a 3/8" hose and the other a 5/16"). When I hooked the lines up, I didn't realize this and used 3/8" on both. I bolted the tank in place, and then realized the problem when I went to hook the rubber lines to the hard lines. Would getting them backwards cause this problem or some other problem? If so, I might try switching them. If that doesn't work, I will probably have to drop the tank and re-do the rubber lines (which I would rather not do). Any ideas? Thanks in advance.