Josh:

I had a dyno after every modification. For those interested in the downpipes they are good for around 10 hp. Mine were worth 11 but the level of modifications will make a difference in your results, IMO.

I had a pre install dyno, open headers dyno and headers connected to the stock resonator back system. Unfortunately the dyno was set for 4wd so the results were unusable. For a while I had the redline raised and can tell you the headers make a huge difference above 6000 rpm. I had to lower the redline back to stock because the transmission took so long to shift at the higher redline that I kept hitting the rev limiter. I suppose a valve body would have solved the problem. Even with the stock exhaust from the headers back, they sound mean as heck. Did you fab a custom exhaust?

Les