[hurryinhoosier62]

Originally Posted by Sirrotica

This one perhaps? made by Nitemare Performance Products:

http://nitemareperformance.com/pumpshaft.html

It appears that they test for hardness after manufacturing specifying 28-32 Rockwell hardness. Those are the same hardness specs that were used to determine if the Pontiac OEM SD rods were within hardness specs.

I've also taken apart a couple race engines that the tangs were starting to spread, although I never saw one splinter up the center of the shaft as the OP's has.

Brad, it could be a case of the hardness exceeding the spec, making the shaft brittle.