Oddball car - swap to disc - ideas?

1976 Dodge Dart Lite. Car was supposed to be big bolt pattern disc, with 4 speed OD. Mine is very early 1975, and is small bolt pattern, and drums on all 4 corners.

I have searches ScareBird, they only service up to 1972.
Ebay listings show complete kits for 395.00 but all say that 75-76 use different upper arms.

It appears the asumption is that 73-76 will already have discs. It is my understanding that /6 cars in these years had drums. Besides a factory setup, does anyone have any ideas?