I have some cutouts on my truck directly after the headers. Basically just take off the plates and you are running a open header. I've made runs with and without at the track on three different trips. Thought I would share the results for those interested. I consistantly gain up to .5mph and ~.05 seconds in the 1/8th mile. I'm guessing around a .07 second and .7mph gain in the quarter?

Not very impressive numbers. They are compared to a full Bassanni exhaust. Still and improvement though. For those running 12.0s or 13.0s and can't seem to break into the next range it might be some good info to have.