Here I simulated a normally loaded truck to set the spring shackles' angle by adding 200-plus pounds of weight on the bed, because my bed and gas tank were out. If the shackle is facing too forward then the spring can suffer from axlewrap. If the spring is too far back then the overall spring travel can suffer. Ideal placement is to have the shackle just past 90 degrees, or the bottom facing the rear. I also used four huge clamps to hold everything into place.