Need a rebuild?

I think I cooked my motor...

I left a bung out the other night when we went riding. Thought something was odd when she wouldn't pull out with 7 people on board. It's not that heavy for her. Turns out the whole floor space was full of water. I would guess around 2000# plus 7 people on board plus the 500~600# ballast tank up front. Wake was massive but it got real choppy on the way back to the ramp so we had to go slow. Obviously didn't go slow enough...

The motor started to get hot so we shut it down for a while. Started it back up to try to limp in since we were getting blown the wrong way and it stayed hot then sort of sputtered and died. Had a go at it yesterday and it seems hard to turn by hand (with the plugs in, haven't tried with them out) the starter motor doesn't really want to turn the motor over, but it isn't stuck solid, it is moving and sometimes it will do a full rev or 2. Won't start though.

The motor is a 350 Chev, Edelbrock Performer 320 hp tune.

The oil doesn't seem to be burnt, there is no water in it either.

If anyone could offer any advice on where I could start with trying to fix it, or figure out if it needs to be torn down I would greatly appreciate it.

I'm planning on going back tonight to try the motor with no plugs in it to see how freely it will turn then.

Thanks.