I was told the sleeves move around too much as well as the main caps. The KB uses 1/2" studs in the head and mains, the BM don't. Seems the block was cast using the cast iron mold. Just not enough material in it for any thing over 700hp.

http://www.youtube.com/watch?v=aIxaesJ190U

http://youtu.be/lCZAaN7fFLg