[Mark Worthington]

John, I have to respectfully disagree with you. Yes, a roller cam needs to be carefully broken in (this should take about 20 minutes), and care must be taken to vary the engine rpm during break in, but I've seen too many dedicated race engines broken in on a dyno to believe in the 1,000-mile rule. While I'm certainly no expert, most of what I've read says that once the cam has been run in, the best way to seat the piston rings is to generate high cylinder pressure by doing a few top-end pulls under load.