My guess is that someone at the PRW factory stamped a set of 1.50 rockers with the 1.60 ID and then they got boxed and sold as 1.60 rockers. PRW gave me a set of their steel rocker arms when they first came out for a magazine article, but the rockers were a timebomb so I never used them. The rockers had ribs around the roller tip that were too big. The ribs hit the valve lock before the roller hit the valve stem so the load was all being carried by the valve lock. I never even started the engine when I saw that. Just boxed up the rocker arms and sent them back and never included them in the article. I assume they fixed this design flaw but I haven't looked at a set since.
I had the same issue with the ones that 440Source marketed briefly. Put them in the mill and fixed them.
Rocker body wasn't spot faced for the jam nut and when you tightened it down, it broke the adjuster. Source replaced them with new and improved but still had to trim the roller end.
Then discovered the adjusters were made of glass. Replaced them with Comp adjusters and thought we had beat them into submission...
Some time later, I had a valve cover gasket leak that was a big blessing in disguise. Pulled the cover and found one side of the roller end was broken on one rocker and when I took them off the engine discovered the rollers were loose enough on their axles that you could hear them rattle from across the shop when you shook them...
Shoulda just bought the Comp Magnums...
Kevin
