A 165 will toy with a 10' disc. No duals needed. We have heavy clay here, and hills to boot. My 165 handles a 10' IH 370 disc, sunk to the axle, @ 4-3/4 to 5 mph I pull an 8'er with my MF150.
You've got something out of adjustment on the Massey disc. Set correct, a #25 MF 3-point disc does an incredible job of leveling a seedbed.