My truck died while I was driving and it wouldn't start back up. I replaced the alternator and starter and it still won't start. There is water in the oil, what would cause this to happen?

Its a 6 cyl. Not running hot. Oil level is way over full now, engine cranks but doesn't start.

No reply, answer removed! .. Apparently a waste of my time!!!!

Actually on the 4.3L Vortec engine it more likely the.......oops!