Because our rides weight as much as they do, there isn't and single mod or even light combo of mods that will make any real "holy ****" noticable performance difference.
I think all the header talk is due to a new generation of used H2 owners taking over and wanting to mod...now that you can pick one up pretty reasonable. I would't spend the money on it unless there are issues w/ stock manifolds leaking or broken bolts.
I've never heard any complaints against the GM gaskets. You definately want to use good high quality header gaskets. The cheap ones will crush and expand giving you constant nightmares keeping the damn bolts tight. Believe me on this...I'm getting the gaskets swapped out on my LS1 on monday after dealing w/ that **** for the last 5 years. The shop is putting GM gaskets on it. I dont have the patience anymore to work on a f-body.
There is no chip on our rides...You are going to want a tune installed. You can get a mail order where you send out your computer to get programmed - starting out around $250. Id check out performancetrucks.net and lstech.com. Alot of good info there. Get a hold of one of the higher volume tuners, you can just tell them your mods and they most likely will already have a dead on tune for your ride.
I'd just keep what you have from cat back untill its rotted out. Again your not going to notice any performance difference.
Ceramic will look like **** after a while also, I wouldn't pay extra for it. My next set will be wrapped- cut down on engine bay heat.
Every motor I've run on stock tune w/ headers has felt like I lost alot of torque. Custom tune has always got that back.
Post pics and make sure to give your opinion on the install, performance, etc..