Sorry , i was refering to box squats and goodmornings.
they both work most of the same muscle in the posterior chain. glutes , hams , low back , ECT. High pulls ,esspecially if done off the floor, will work the same muscles as well while throwing in the added work on shoulders , traps , and upper back. Its really up to you which day to do them. I would combined the heavy wquat and deadlift day into one day and do high pulls with that day. Are you doing them light or heavy?Reps? What kind of box squats are you doing and what else do you do on your heavy deadlift day as of now?