The cam was a Comp Cams 280H.It's been in there for 3 years, about 5 or 6000 miles. The lifters were the ones that came with the cam. I was using Rotella T 15-45.
I am not 100% sure what happened but the pushrod guide was completely worn out while all the others look as good as the day they were installed. I think it's one of those things that I will never know and I can only guess what happened first.