I emailed him and he quickly responded. He said anywhere from 95 ft-lb to 125 ft-lb is fine, but has noticed bolts coming loose at the lower end if running the truck hard. I put blue lock tite on all the driver side bolts and went to 125 ft-lb. On the passenger side I only loosened the bolt so I wasn't able to lock tite it and I only took it to 96 ft-lb. I might try to bump it up later to maybe 105 ft-lb, but I'm not chasing Raptors so I feel confident it won't be coming loose. I marked everything with a paint pen.
Also, as an FYI to anyone else thinking about installing this kit, I had to almost completely remove the tab on the factory mount for the ABS wire in order to get clearance for the nut. It's best to remove the rear driver side wheel to get some space to work. I started off with a hacksaw blade because I didn't trust myself to not nick the ABS wire or the brake fluid hardline with an angle grinder. I ended up not cutting off enough of the tab. At that point, I decided to pull out the angle grinder. I pulled the ABS wire as far away as I could, zip tied it to the suspension coil and covered it with a rag to protect it from flying sparks. I also unbolted some tabs for the hardline so that it could be flexed down and zip tied to the axle and out of the way as much as possible.
I should've taken some before/after measurements, but the kit does seem to have better recentered the rear axle when viewing from the back.