Upgraded exhaust without headers? worthwhile? pointless? someone help :)

[ohsmily]

I have a "cold-air" intake on my 6.0L 2004 Denali XL. I am seriously considering putting an aftermarket (probably Flowmaster) cat-back exhaust system.

Is installing a higher flow exhaust system pointless without also putting headers (besides the nice sound it will make)?

Basically, will the stock headers negate any effect the exhaust will have? I might eventually put headers on, but for now, it would just be the exhaust or nothing (and I already have the intake on there).

Any feedback is appreciated.


(as an aside, does installing headers in a 2004 Denali XL require a professional mechanic or can someone who is very mechanically inclined take care of the job without the risk of really destroying an expensive part of the vehicle. Also, are there any special "mechanics" type tools that are needed that would be prohibitively expensive for the job)