Watch out for those World blocks dakotafarmer. My dad (Greg Fernald of SS and AFX) has built a lot of them and has come across defective blocks from world industries on several occasions. Yes, World is the manufacturer for the new Mopar branded hemi blocks. problems like blocked off oiling passages, and pinholes in the rear of the block are but two of several examples he has encountered using their blocks. Most have turned out ok but that is one expensive motor to build so quadruple check everything! Stage 5 is a great source for heads and valvetrain.