The kit you are looking at is specifically designed for leaf spring perch spacing... using an axle that the kit is not designed for will require you to make extensive modifications to the kit itself. Use the axle the kit is designed for and have it semi easy... use a different axle and have it not easy at all... or do like actual builders do and fabricate your own sas kit to utilize any axle of your choosing. Then you can join the "pulling my hair out over this shit" club:rolleyes: