Super Springs mounting kits have one simple function; to induce some preload tension onto the installed Super Spring. This is done to ensure that when the up fitted vehicle is unloaded, the Super Springs operate silently. The 2" tall mounting brackets act as fulcrum points on the underside of the Super Spring and the shackles at each end of the springs secure it in place, pivoting as load is transferred to the springs. The mounting brackets bolt to the vehicle spring pack on either end using the U-bolts, cross plates, washers and nuts provided. All nuts provided are nylon self-locking and will not loosen when correctly installed. After installing the mounting bracket, tighten the U-bolt nuts while the vehicle is off the ground. After the Super Springs are installed and the vehicle is on the ground, retighten the U-bolt nuts. MTKT vs. MXKT. Super Springs produces two versions of the mounting kit; MTKT and MXKT. The leg-length of the U-bolts provided in the MTKT are 4" long. If your vehicles spring pack has had extra leaves added you might require the longer, 5 1/4" U-bolts supplied in the MXKT. To verify the correct kit please measure the height of your spring pack directly above the axle. If this measurement is less than or equal to 2 3/4" you will need the MTKT. If the measurement is greater than 2 3/4" you will need the MXKT.