Anyone install Gibson Log Headers (lessons learned?) or JBA Shorty headers?

Also looking at using a Flowmaster (steel) $500 Y pipe with the cats but plan to use stock cat back water heater muffler but remove the resonator / replace with less resrictive tail pipe muffler, depending how much louder...

Dynatech has Complete $1,500 stainless Headers and Y-pipe with cats for HEMI but does not show for 2008...only 2007


Also does anyone have any recommendations on headers and their actual / real performance improvementsand gas milege increase or decrease.

I've read some other blogs that say if you open up the exhaust on a HEMI you will kill low end power and thus kill mpg.