I just joined, so I'm a few months late to this thread...... I used the 2.5 spindles and clipped one full coil and ended up five inches lower even though I only expected about four (the extra inch came from indexing the "D" opening in the top of the spring properly) I'm using the narrow (6") chevy truck ralleys' that came off a van and I was using 225/75/15s without any clearance issues. When I'd hit a dip too hard the treads would rub the top of the wheelwell. I'm thinking that a much bigger 75 on an 8" is not gonna work, but you never know!