I don't like seeing the shackles hanging down when they've been inverted. If you hit a pot hole, etc., the shackle(s) could revert to their correct position, thereby upsetting the handling, possibly at the worst time. I'm not a fan of air shocks either because shocks have the job of controlling rebound; springs are designed to carry the load. However, I would choose air shocks over inverting the shackles. I put new leaf springs on my 55 Tbird; they were purchased from General Spring KC in Kansas. After installing them, along with 15 x 7 wheels/w 215 70R15 tires, I decided I needed more clearance. I removed the new springs, took them to Dentoni's (Stockton, CA) and had the new springs re-arched to provide an additional 1 1/2 inches of clearance. Had I known, I could have asked General Spring to build in the additional 1 1/2 inches.