WHAT SIZE HEADERS TO GET ON A CAMMED L98 WITH HARROP 2300FDFI

[Not_An_Abba_Fan]

With forced induction you need volume as well as velocity, 1 7/8" will be better. 1 3/4" will work, but 1 7/8" will work better. What cats are you running?

 

[moveage]

See what everybody knows is more flow under load and high rpm, that’s not the issue.
Not WOT at peak torque driving 30% never mind 95% of time. That’s the issue, torque management and badly planned exhaust.