You can't really set a lathe to max. You can only tell it to take 1/1000th's of inches off, and about 8/1000th's is all you can take off before the lathe cuts too deep and the drum catches on the bit.

Besides, if they guy's never done drum brakes before, how's he going to 'keep an eye on them'? He doesn't even know what to look for.

And if you do need drums, get them turned before you put them on the truck. Even brand new drums can get warped by the time they get to you. The get thrown around by shippers, stored wrong, etc.

Also, get a disc sander attachment for your drill and clean up the raised areas where the shoes sit before you grease them up. Try and grind down any notches there from old shoes. White lithium grease works best.

Other than that, take your time, and do like the other guys said and take one side apart at a time. Be careful to put the brakes back together - every detail is important. Also, the cable likes to slide off the guide while you're putting it back together. Make sure it's in place.