I'm thinking of getting a set of 6" rear springs to be used with a 2 1/2" ORD flip kit for the back of my K5. I've seen the posts about getting the Ford 57's and IFS 63's but I still have a couple of questions. Of all of the popular springs to choose from which fit the OE size hangers? How about the center pin placement? I was thinking it would be nice to find a set with the center pin about an inch back (from the OE 52" pin position) to offset the push forward from the flip kit. Also, since I'll be putting the flip kit in a "custom" position what is the preferred shackle angle? Straight down, angled back (if so, approx how much)?