If you purchased the Strange kit for a 1969 "B" body and you're replacing disks that are already on the car then the problem is the spindles. According to Strange that kit "Fits factory drum brake spindles."

I suggest you try to find some stock '69 "B" body drum brake spindles. They shouldn't be that hard to find and if you indeed have that kit, everything should fit properly. That said, putting the later spindles on a '65 may change the geometry slightly and effect alignment. I'm sure someone will chime in who has done that before. If not, ask your question on the "For B Bodies Only (62-65 forum). Lots of early "B" body knowledge there.