Ignoring my wife's advise,a few days ago I sold my low mileage, super clean 04 150 4x4 so I could buy a well used , 99 crew cab dually 2wd Lariat, so I could pull the bigger camper that I had just convinced her we needed. All in all truck is in good shape, body clean, interior so so, but what made me jump on it was the engine .All new up top, including low and high pressure pumps, injectors, harness,v.c gaskets.... all from ford (3800 in parts )and all done last month.Tranny and rear end recently gone through, so I figured it was a great deal .Long story short, the day I bought it, it ran stellar ,for 480 miles (up and down the Fancy Gap , walking the dog). At the 481 mark, it started skipping and smoking at idle, with a pretty good knock.Buzz test good, contribution keeps failing no 7. I swapped injectors, and no 7 still misses and smokes. Hard to tell if it is black or blue, but it isn't white. Seems to go away under load, but I'm not sure.It sounds like extreme leakage into the crankcase, and does have lots of pressure at oil filler. I am going to borrow a compression gauge Monday since all I have is car stuff and check. Broken rings on one piston doesn't make sense. Any ideas