i am in the process of doing a 3 link on the rear and a 4 link on the front of my buddie jai birds rig. it will have a pu cab and a wheel base strech of 35". but i am not sure of which coils to use. i have heard of the tracker coils and some of the mercedes are supposed to be real long and soft. but i am trying to save some time here. and pick some minds. later mike