The best way to answer this question is to look at the dyno thread. A lot of people are going by feel or what they want the very expensive header they just bought want to do.
Catless + E85 completely eliminates the torque dip. Catless header + 93 mostly get rid of it. There are lots of dynos of catless + dead dinosaurs that showcase some torque dip.
Of course, FI gets rid of it, but I assume you mean to stay NA.
http://www.ft86club.com/forums/showthread.php?t=55450