I have built my own perches for the Ford 57" springs I plan on installing in the rear of my K5. I am going with ORD's flip brackets, swapped left for right and right for left, as I have seen reccommended here. My question is: How far off center should I drill the perches for the spring center pin? I read the old writeup on echobit about the ford 57" install, and the member who wrote it redrilled the springpack for a new center pin location, but I don't remember how far forward, or back it was drilled. Anyone know the best distance to offset the spring perches from the center pin?