I just replaced the rear disc pads and rotors on a wrx. Since the swap, the parking (drum) brake won't hold the car as it should. Is there an adjustment to tighten it up? The drum shoes were not changed.

 

There are two places to adjust it.

Inside the rear brake assembly itself. There is a gear looking screw that pushed the parking brake shoes apart.

And, you can fine adjust it at the parking brake handle.

Have you just swapped the pads of the parking brake shoes as well? What kind of rotors did you get?

 

swapped the oem disc pads and rotors with new oem parts. the shoes didn't change as they don't wear much and had plenty of life (visibly anyway)