For Machamp..
You wouldn't need cross chop, if it's ability is No Guard. I would drop Cross Chop for Stone Edge, to hit flying types harder. If you plan to have Guts, keep Cross chop but take out Dynamic Punch for Bullet Punch.
Dusknoir is meant to be a tank, and has that low HP, so having Pain Split is a great idea. I would suggest Will-O-Wisp to cripple physical opponents. As far as the the other two slots, you should put moves that can take out things it can't for example, have Earthquake to take out steels.