I got lucky and my block and crank were fine. If they weren't, I would have looked really hard at PG's forged short block. Its 5k, but you get it assembled with good parts. a used motor will cost you a little less, but you will most likely blow that one up too! Ken will set you up.
I was getting a lot of KR around 6-7 after the cdfp internals and was supposed to get it tuned out yesterday but the engine did not make it. I don't know if this was the cause or not. Others have made speculations that this was the reason but I don't know.