CRAP! I'm smoking!

Reversion is common on larger cam engines that have heads that flow well at low lift. The marks are usually more carbon from fuel (and wet, sticky deposits) and you'd see them way back up the intake ports if that was the case. I doubt it's oil rings but it's possible that the 2nd ring isn't fully seated. The top ring is the compression sealing ring. the 2nd is to scrape any oil the bottom rings miss. 2nd is not a compression ring although the oil typically on it does give it more sealing properties. Get the intake to fit, and then drive it a bit. You may find the smoke goes away after a few hundred miles.