rabbit inserts for super

[721302]

i am doing a set of lowered struts on my 72 super and bought a set of 1980 rabbit strut inserts to use as recomended over stock inserts but they are about 2 inches to short in the housing. i have heard about using leather to make up some room in the housing but i wouldnt think you could make up a 2 inch height differance by stuffing leather in the stock strut housing. I also read that you have to machine the shaft under the threaded part for the stock upper bearing,but mine fit perfect on the bearings. Maybe autozone sold me the wrong inserts or something? Let me know if maybe a i need a different year rabbit inserts or how to make up the height difference.