318 Dis-assemble & Assembled 1st time

Oil on the combustion chambers comes from 3 places. Either the rings let it by, it leaked past the valve seals because of bad seals and/or guides, or it leaked into the intake port from the intake gasket. It's very rare that PCV would introduce enough to keep a single chamber wet. I suppose possible, but rare IMO. If your rings have .050 end gaps, it's because the bores and rings are worn. Normal and fresh engiens will have anywhere from .020-.030" depending on a lot. Brand new rings have .018-.025ish. Maybe more depending on pistons. your leak down isnt too bad. I'd be looking at the stems of the intake valves. If they are wet with oil, or covered with black coal looking gunk, you need the heads redone. Post pics if you can...