Hm, this makes me wonder if Houston or Hervey have "tuned" their headers. Exhaust pressure is easy to check, so I don't see why not. You can check your exhaust pressure yourself if you want. Take out your oxygen sensor and stick a pressure-tapping tool in the bung. I think (and my memory may be faulty) that the general rule of thumb is that it should be no greater than 2psi at 2500rpm. Farrar Hudkins #2613 Paul Gress wrote: > > > > > This has to do with "exhaust scavenging". > > This is what "tuned headers" are suppose to do. This is why tube > diameter is critical at an RPM. The tube diameter is usually tuned to > operate at the maximum horsepower or torque rpm. . > > Paul ------------------------------------ To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnewsYahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: mailto:dmcnews-digest@xxxxxxxxxxxxxxx mailto:dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/