I really hope the block works, cuz I saw some posts of a member (jaydee16 or something) saying he had made several blocks which all failed...
edit: check this topic
http://forums.procooling.com/vbb/sho...5&pagenumber=1
But maybe they all failed becauce the "jets" (of whatever they are called) dont go into the holes...although I couldnt believe he would make the same error over and over and over again.