OK lets ask this
after water got into motor, did you STOP and split case to clean any possible crap that got in with the water??
if not, well, that crap is maybe eating up your new TOP end parts
your NOT the first to have this happen
and THAT is why its said, the ONLY Correct way to FIX a sunk motor, , a motor that sucked in WATER,, is to break it down split cases and CLEAN ever nook and cranny!
NOT doing so, JUST Flushing, DOESN"T remove that crap
SOME YES, get lucky and can drive for yrs, BUT as they say, FEEL LUCKY??
as NOT splitting the cases is like a lottery ticket, a gamble
I know this maybe isn't what you want to hear, but its the way it works
JUST a top end on a bottom end with crap in it, means SHORT life to the NEW top end, more times than NOT!
SO< ??
you MIGHT have excess oil in exhaust?? BUT I sadly think, you still got crap in your motor! that maybe ruined your new top end!