I thought this might be an interesting topic. Among the articles I've read, I have a Dave Gierke one that talks about break-in, and in the article, he says ABC engines were originally non-throttled, and meant to be run wide open at all times. He said that idling, and cold running and rich operation wears them out. So, I was wondering if after break-in, it was best to get them to full throttle, as soon as they are started up. I try to start mine and get it wide open pretty quick, and avoid as much idling as possible. I don't have any long term results yet.