Will this work on a 1976 Dart sport with power disc brakes in the front?

junkyardhero said
that is incredibly cheap. like, suspiciously cheap...

and it looks like universal chevy parts...

Yup. Universal "Fits all" setup that fits nothing equally well.
They can be made to work, but what's wrong with factory-designed parts that you KNOW should fit and work? Brakes is not the place to cheap out.