It's been a long time since I made these, but I had the urge, so I picked up a small (just over 1lb.) rack of spareribs.
They spent last night in the fridge under my own rib rub, but I'm working from a recipe with following directions:
Preheat the oven to 300 degrees Fahrenheit. Remove the baking sheet or broiler pan from the refrigerator. Place the ribs into the oven and roast for two hours.
Remove the pan from the oven and take off the foil. Use tongs to flip the spareribs. Replace the foil and place the ribs back into the oven. Cook for another two hours, or until the ribs reach an internal temperature of at least 165 F, although 180 F or higher is more ideal for ribs that fall off the bone. Remove the foil from the pan for the last hour of cooking.
Four hours @ 300? Seems like it ought to get to 180 before that. In fact, I may just pull them @ 170.