Called Dr Gas and they didn't get into the game till after the V6 days. They said that an X-pipe probably would do something but not a whole lot since the firing events are atleast 240º apart between banks on an even fire V6. I lost Mike's number. My engine is far from high enough compression to really need a kill exhaust system but since the 78 manifolds won't fit with the 8445 heads it's not a far expense to get a set of pacesetter or simular headers.