Is it hitting the frame in front of the shackle mountinghole or in back? On a Cuda, I thought it would hit the valance before it hit the frame. Also, did you do a side by side comparison of the springs to ensure they are the correct type? Espo is good, but they aren't immune from the occasional human goof. Fai.ing that, can you give us teh measurements of the spring from eye to eye, and front eye to mounting pin?
Also, like changin gears asked, what fornt hangers do you have? The additional 2" length in some offset hangers could have shoved your whole spring pack back too far.