I wiped out my first cam a couple of weeks ago. I took out #4 and #8 exhaust. Installed in a 400 sb. Cam specs can be found here.
The engine was not built by the machine shop. The cam was broken in for me by an experienced High Performance engine builder. All parts were new, engine was line honed, parallel decked, torque plate honed, balanced with ring gear and balancer. After disassembly we took the parts to the machine shop for their opinion. They said, that their cam failure rate has gone up 300% in the past 3 yrs. They blame it on poor quality control on lifters. According to them, lifters diameter specs have declined in recent yrs.