I’ve owned my Aspen R/T since 2000 and in 2005 I put TTI step up headers on listed for B-body and they’re a great fit and still work great on the car. It’s a 408 Stroker and we tested it on the dyno with these headers and a 750hp carb and it pulled 537hp/540tq. Tried a 830 carb and 1 7/8” headers and pulled 550/550