Erthang you need. Searchy searchy never fails
http://www.grandprixforums.net/safely-modding-your-3800-powered-car-17482.html
Hmmm that'll probably really help him mod his 5.3L V8 right?
Headers are the cheapest hp mod.
Ultra-Complete Kit
HEADERS 5.3L LS4 FRONT WHEEL DRIVE HEADER 2005-2009 IMPALA SS/ MONTE CARLO/ GRAND PRIX GXP/ LA CROSS at Doug Thorley Headers dougthorleyheaders.com
Doug Thorley headers Good? Bad? - LS1TECH
What are the power gains anyways?
Doubt its worth it.
Just save your pennies for a turbo.
Cartuning Performance
Oh kevin.
Gains aren't worth noting on a stock engine. A built engine though is a different story. And some people prefer the N/A compared to F/I like myself.
remove interrior, done. racekar!