'75 pinto 10" rotor and caliper

[jmerson]

I'm sure this has come up in the past but i searched for it and got nothing. I have a '34 sedan with mustang front end. The caliper has a casting number 4109 and an emblem " Ford". It has a 10" rotor that was a 4 bolt rotor but it has been redrilled for 5 studs. I measured it and got 4.25" spacing but maybe i measured wrong because all i can find for 10" is either 5" or 4.75" or 4.5". Any one have any experience with this setup??
I want to get new rotors, calipers and pads.