FBO springs

I asked don he said try the silver ones. Wasn't really as informative as I hoped. I figured there would be some kind of chart with the springs or somebody that had used them and knows what they use to get the curve they have. Also I ordered it from him on phone and he charged me more than the kit sells for on eBay. I didn't know the kit was sold on eBay or I would have ordered it there and saved $4 and if I knew the book didn't have useful information I wouldn't have gotten that either.