GM had a recall done on the ecotec line because of the block failures they had. They went from expanding foam to sand casting, and it worked out well. As far as internals, my LDK block is holding pretty well. Honestly if you have any other questions I suggest contacting the guys over at ZZ performance. They are wizards with the ecotec platform. I actually bought my LDK block from them, and never had any issues. Here is the motor you have.
http://shop.zzperformance.com/store/...ong-Block.aspx