finding disk brake for my 72 swinger

I have been looking for 2 years now, no junk yard around me has any cars the oldes they have are in the 80's. I have found acouple different swap meets but they wanted any where from 800.00 to like 1000.00 :cussing: for them. I thought that was too much for them.
I have a 72 swinger with 4 wheel drum and I want to change to disk up front. I am running a 400 bored 30 over 12.5 to 1 the motor dynoed at 720 HP.
So I need more stoping power any help on where I can find a junk yard I can get them from or anywhere eles would be very help full
I live in North West Indiana Thank you Brian