Ok here is the deal.....When I first built the engine I was under the understanding that you want to center the travel of the rocker arm on the valve stem. I had no concern of how wide the pattern was. It is to my understanding now, that you want the narrowest pattern. I found some pushrods that where listed for BBC hyd roller cam applications. So I compared them to mine, .400" longer on the exhaust for starters. So using my pushrod length checker I did a pattern check with both. The ones I currently have in the engine provide a "centered" pattern, but it is really wide. The .400" longer pushrod provides a very narrow pattern, but favors te exhuast side of the stem.