No the ridge is not normal. Some manufacturers have a machined step there;the lower bore receiving the bearing, while the upper/outer bore receives the grease cup. I don't recall the 10 inch hubs being that way. In any case the outer bore would be larger than the inner bore, and would be commonly called a step. A ridge impies that the inner bore is larger than the outer bore, and that would make it impossible to install the race.
For street duty, your DB set-up is more than adequate. A good quality grease, proper adjustment, free caliper ways, and freely moving caliper pistons should be right on. I set the bearing adjustment to the loose side of the spec. On fixed caliper systems like my KHers,this lets the spinning rotor "knock back" the piston a few thousands, and let's the wheel spin free with no brakepad drag. On a floating caliper system this may not be as effective, but I still do it; leaves a bit of space for the hot grease to find.
Four wheel 11 inch drums, on a streeter,IMO would be overkill. In fact a 9incher in the back,running unproportioned would probably work just fine. A front DB in the 10 to 11 in diameter, should be just fine. If you need more stopping power, a switch to a grippier pad might satisfy your needs. I am talking street-duty, and occasional track time with typically sub-400 HP. If you are trapping 120plus mph and running back to back, and with a short shut-down area,well then, more brakes should be considered. But for typical streeters, your sizing is lots.
Plus the 11 inch system is HEAVY.