Dave, the rods aren't forged stock are they?
Have you found out yet why they failed? I mean if there is/was a problem with the rod itself, I would contact the company you got them through!
Stock rods are forged in all 60*V6's.

The LG5 rods are *supposedly* a better casting or something too, but nobody has provided any documented proof of that.
If you look at the side of rod, you'll see a wide flat spot, a tell-tale sign of forging. A cast rod will have a narrow line, almost coming to a point. Look at the first pic Davis posted and you'll see a wide, flat area running down the length of the rod.