Yup it's a standard truck 12 bolt. Baer brakes make 4 different kits for these rears. I'm using their smallest one since the rest are more expensive and overkill for my forseeable needs.
https://baer.com/12-Rear-SS4-Brake-S...e-4302468.html
Matt's Classic Bowties offers really good pricing on these through the forum, which saved me more money.
I ended up having to mill down both the inner circle and outer diameter of my rear axles so they'd fit the rotors flush. Baer said this isn't unordinary and that I could turn the rotors or axles, either was okay. I figured I'd do the axles so future rotor replacements would fit. Baer said they could pre-turn the rotors for me if I knew the size when ordering.