evinrude 140 crossflow troubles

[usmma2013]

hey guys,
Just finished rebuilding an evinrude 140 crossflow v4. The powerhead on the engine was scored and needed a hone, I had a spare powerhead with good compression. I gave it a light hone and new rings and used all the carbs, fuel pump, and electronics from the original engine. I started it up and after about 2-3 minutes got an overheat alarm. I shut it down and the port head (from behind the engine, looking forward) was very hot to the touch, the stbd was slightly warm. I checked the t-stats they were fine. I also disconnected the water hoses running from the block to the tstat housing and almost the same amount of water was flowing out of each head. Next, checked the plugs. All on the stbd side were fine, the top plug on the port side was clean, like water intrusion. Now for my question, what could be going on? I'm hoping someone says something like the head could be cracked and all I have to do is put a new head on (I have several extras). The engine had all new head. exhaust, and water gaskets.
thanks in advance!