Re: factory disc brake off 66 galaxie on drum car
The bolt pattern will be the same (5 x 4.5) for just about every full size Ford into the 70s and beyond. I think some Lincolns went to 5 x 5, but I'm not sure.
What typically comes into play for disc brake conversion is the size of the centre hole. As an example, my original 65 wheels won't fit over the 71 LTD rotors I am using because the centre hole is too small a diameter on the wheels. Nearly all aftermarket wheels will fit, or wheels from the car on which your rotors were original fitment as they have a larger centre hole bore.
1965 Galaxie 2-door 390 FE