you cannot downgrade. you could upgrade but in your case, the rear would not support the needs of a 3/4 ton truck

Roy

First off I have 64 c10 and with upgraded suspension ... Look at places like brothers truck and cpp( classic performance products) there kind of pricey for the whole kit is around 1500$ but it has front and back disk brakes a dual reservoir power brake booster all the hard ware and excreta http://www.classicperform.com/Store/Brakes/6366cbk-6.htm Its an upgrade not downgrade