I have a 66 c10 that the PO did a disc brake conversion on, I'm wanting to install drop spindles, all the drop spindles i have seen say must use with 71-72 disc brakes or EQUIVALENT . Is the disc brake kit on my truck EQUIVALENT? the rotors are 1 1/4 thick ... I don't know if i am reading this right ,are the disc brake conversion kit for a 66 c10 the same as the 71-72??? I just need to know if ill be alright purchasing drop spindles that require 71-72 disc brakes, will they fit my 66 disc brake conversion? THANKS