I do our baby backs this way: (I saw this on Oprah years ago but I modified it)
Put the ribs on a rack in a large pan. Add a little water (or juice, or ?? This was one of my changes to the Oprah recipe, hers had no liquid added.)
Dry rub on seasonings.-Salt and Pepper, garlic salt, Greek Seasoning, or anything else you like)
Completely cover with foil. Make sure it's all sealed up. Put in oven (I do it at 325 usually) Cook for 3 hours. Check to see if they are done. If they are remove the foil and then I do one of two things:
Leave the ribs in the oven, turn up the heat to 350, apply BBQ sauce ( I like Sweet Baby Rays) and cook for another 15 minutes or so. Since the ribs are already tender I don't need to cook them any longer, just brown the sauce a bit.
Or take them out of the oven and put them on the BBQ. Sauce both sides. Watch carefully as you don't want to burn the sauce. Also, since the ribs are so tender they can fall apart before you put them on the grill. If I'm going to grill them I cut them in smaller sections, like 4-5 bones each. Easier to handle.
We are actually having baby backs tonight. I just prepped the ribs (pulled off the membrane, applied seasonings) and they are waiting in the fridge to go in the oven about 3 p.m. We plan on eating about 6-6:30.
This method is no fail and is super easy to do. Even though you are doing larger ribs, the procedure should be the same. Cooking time will probably be longer and you may want to drop the temp a little as well.