From what my research has shown one is much better off converting to 72 chevy spindles which include heavier bearings. Here are links to the kits I found so far. (I am doing a 66 gmc with 6 bolt rotors. The difference in the kits is that they include everything but the pump mounting bracket. oops went and checked on the 1960 year model at Americanclassics.com go in and look around you will find the kit you need and the options you want. for some reason I could not get a copy of the link to post here so just go to
www.americanclassic.comand search for disc brake conversion kits do not forget to enter the year of your truck. Kieth
www.americanclassic.com/br3511