I know I'm a few years to late but I just put kffl-57sl in front and kfrl-68ssl in the rear of my ba xr6 and it's not low enough in the back about 20mm higher than front I'm going for the sssl witch are ultras for ba witch it's suppose to be, sl and sssl are ment to go together they are ultras sl and ssl are ultra front and super low rear. It's wired but that's what it is. Don't make the same mistake I did reading all this sh*t just call a shop that specialises in king springs and ask them I've read over nearly every ba lowering forum and everyone has a different idea of what's low so just call up and do it to the hight you want around tire to gard hight is ultras for my xr6
