360 c.i. (1-3/4" - 1-7/8") after use at race track (shown with stainless steel muffler)

410 c.i. (1-7/8" - 2") brand new

Kevin Ramey (7m) of Fort Worth, TX running Rocket Headers with ASCS racing series.

 Brian Monteith of Phoenixville, PA running (and winning) with Rocket Headers at Lincoln Speedway in Abbottstown, PA.