It's one of the most common oils I come across, which makes it easy to find. I have bought it at NAPA, Advanced Auto Parts, Wal-Mart, several gas stations, pretty much wherever oil is sold. Mind you - it comes out pretty dirty looking in your oil changes, but that's because it keeps your motor cleaner. I change my oil when it gets pretty dark, about every 5k miles or so. I also run NAPA Gold filters, and nothing else. I don't know about running it in a 2.8, but I'd do it if I owned one if that says anything. I'm no expert, I just am really regurgitating info I've read here before. I do know that NAPA Gold filters are really made by Wix and even have the Wix logo on the box, but they're pretty expensive for an oil filter for an old motor.
I just did some research for you fellas, it's CI-4 rating that you want to see on the bottle, and Rotella T 10-30 is CJ-4, so it does NOT contain proper zddp for a non-roller, so do not confuse the 10-30 for the 15-40, which 15-40 is still CI-4 rated.