73 Duster build named Fred

What Calvert springs did you buy stock or 1" lower? Also what did did you set your pinion angle to? I've always set mine to 1* negative but when I did that with the Calvert setup I had a hellish vibration. I ended up cutting the perches off and setting it to 4* negative. Unfortunately Calvert lists the 4* negative on their website but not in their instructions.