No it was plain water. I wanted to wait to make sure it was going to stay together before I wasted antifreeze in it. Also, much easier to drain water out than antifreeze, and I drained the water out of it like 5 times.
THe water in teh bore on the left of the affected one is from the water jacket (poured in through the cylinder heads as I took the headbolts out, you know how sbc decks are tilted so water ran into the bore as they came off), but for some reason the water in the #6 bore looked like it had just been sititng there rusting for a while. I dont know if it has oil in it or rust from the inside of the water jacket or what. No idea why it looked THAT bad to be honest. It had been sitting in there a week before I got to the point where I could pull the heads, though, so maybe it got that rusty hue during that process? Could be gas mixed in? I couldn't tell you man.
The crack wasnt there when the motor was put together, or at least itw asn't noticable. It developed. I think the water jacket in the block was rusting out and that bore failed first. Im sure hte others arent too far behind which is why I dont want to salvage it.