Fred - It is unlikely the Zard single silencer can flow enough for a good header design. So right where the header SHOULD make more power, the silencer is the restriction. Also, it is easy to really screw up exhaust velocity with a larger diameter header primary or collector. Low velocity gives poor torque.
With a good design, a header can have good velocity and low restriction over a large part of the powerband. The engine that has the best average power, will always beat the engine with a peaky powerband but higher peak numbers.
The stock header is not that much worse than the Zard one - once the precat is removed and a bit of clean up work is done. I really wish Zard or Arrow would have designed the collector correctly.
I'm not sure the Trident 1/2 system makes more power than the TOR's - with or without the header work. Once the engine sees less than 2.2 psi of back pressure, going to more flow has less and less benefit.
Mark - If you lived nearby, I would be more than happy to do the work on your header. But it is nothing fancy or hard to do. I HIGHLY recommend the ceramic coating. It doesn't cost much to do it yourself, and the largest expense is a cheap heat gun - but if you don't mind installing sticky parts, even that is not needed, it just makes it easier and nicer.
