I like to use whatever I can find for free and then make them fit. The Econoline axles work great after you narrow them as they are a little wide. '53-'63 or so F-100 axles work great also after they are narrowed. I take 4" out of the center and then weld them back together. Once you drill them full of holes the Econo or Effie I beams look great. If I can find the pics, I did a '61 Falcon and used 30" long sprint car torsion bars to suspend it. You can run the bars as cross torsion bars, or parallel bars. Ride height adjustments are a snap, and the spring rate is easy to change. There is also very little un-sprung weight with this setup.