69 front disc brakes

1970Duster said
Those are 73+ BBP brake setup. Just use a 1973 plymouth duster 340 and you can easily find parts at the parts store.

Yup, single piston caliper is the giveaway thats its not 72 back original equipment.
Looks like it could be 73-76 A, late B or 76-up F,M,J.