[GMC1967]

I just tried firing up my 1967 292 L6 that I had rebuilt, and it wouldn't turn over. I thought the starter was bad but then I noticed some water (thats right water) leaking from one of my spark plugs, I tried turning the engine over again with the sparkplug removed and water fired out of it like a firehose. I removed all the plugs and then cranked it again, and water is firing out of all cylinders. What is going on? I just had this motor rebuilt, why is this happening? Just trying to get some ideas before I go over to the machine shop tomorrow and raise hell. I'm wicked pissed, good thing that shop isn't open tonight....