Front brake rotor part numbers please... confusion reigns...

[K9COP]

Hi guys. My car is a 1969 build, 1970 registered (probably!  ) Charger with a 440 and a four speed in it. The previous owner added the 11" factory front disc brakes, which are great, but I wanted to upgrade the rotors. I bought 11" drilled and slotted rotors, but they don't fit. I just spoke to my mechanic and it appears the won't tighten down onto the spindle, leaving a 1/2" or so of free play. Given this, my question is, 'is there a part number on the original rotors that I can get to gain specs off to order the correct dimensions replacement rotors?

I accept that I don't know the origin of the disc conversion, hence the need for a part number, or a resource with the rotor dimensions that I can compare to what I have.

thanks guys,

CS

[John_Kunkel]

You need to know which spindle (knuckle) you have; measure the length of the spindle shaft from the tip of the threads to the plate mounting surface then measure the diameter of the two bearing mount surfaces.