2017 Ram 2500 5.7 Gas nearing 50k miles. I want to do a flush to keep the engine as clean as possible before sludge/varnish forms. I'm going to drain the old oil and add 6 quarts of fresh cheap conventional with a quart of Gunk motor flush. Idle 15-20 min, drain and put in PP 0W-20 and napa gold. Any problems with this? I've heard that flushes are best for keeping clean engines clean.