The coils are outside the frame, with lots of clearance. They locate directly above the leafspring perches. The lower links replace the leafs, and are bolted to the diff with U bolts, just like the leafs were. This setup gives a smooth stable ride with lots of susp. travel, BUT! very limited articulation,as the links and the diff are one unit. I am still refineing this setup, and am keeping it as it does work exceptionally well on the street, and so far, well offroad. I am starting a second set of links to help iimprove artic.I will of course keep everyone posted of the results. As this system is so tight, the upper links just help keep the diff centered and control torque. One big advantage I have found, there is NO axel wrap.