X & H pipe vs straight dual exhaust

FWIW - just have to remember that it's not always easy to tell the difference just by "the seat of you pants", even at the track, one may need to change jetting a bit to get the most out of the change and a full system over an open exhaust can weight around 50-60 lbs more. So theoretically, in the 1/4 mile, that's about a half of a tenth difference. (i.e.: If it runs the same, you would actually be .05 faster at the same weight.)