Reply to "Header Size"

You don't have a lot of choices in headers. The biggest problem with Pantera headers is the lack of a proper collector. Too many Pantera headers were manufactured to mate with the OEM tailpipes, which are far too small in diameter. Any header designed to mate with the OEM tailpipes are not worth the money.

It sounds like you already have the GTS exhaust system, which is a good compromise between price, drivability, performance improvement, noise level and ease of installation.

The best header available from the standpoint of craftsmanship and collector design is Pat Mical's header. In my opinion the next step up in improving your exhaust system will be Pat Mical's headers mated with your GTS tailpipes. Adams Hudson is running just such an exhaust system, you may want to contact him for his thoughts.

Whether or not you need a larger diameter tailpipe and better muffler depends upon the state of tune of your motor. A 400 BHP motor does not need the larger tail pipe system, a 500 BHP motor could use it, but I would also point out that David Berman's 408 cubic inch motor with Blue Thunder heads & roller cam is making 540 BHP exhausting through a stock GTS exhaust system.

Quite often a low back pressure tail pipe & muffler system will give the motor a harder "hit" when it comes on the cam, and make more noise, but not really increase torque. The harder hit is caused by a dip in the torque curve between 2000 and 3000 rpm resulting from the increased size & lower back pressure of the "larger" tail pipe system. In my opinion a hard hitting powerband like that is detrimental to drivability.

cowboy from hell