So i keep on thinking on swapping out the old manifolds for some headers and a buddy of myne with a formula is in the process of installing some on his and said its a real Bit** to do. but i also heard that your stock manifolds are pretty hard on your engine cause it can't breath as well as it would with headers.Anyone know the price range in having headers installed at a shop?and are they really worth it?

F--K YEA theyre worth it! the stock one do make your engine choke for one the Y pipe that you have is freaking sucky, but to make things flow better, get your self a good flowing exhaust. i got a magnaflow and im gonna go with the hooker 2055's for a full exhaust. for a shop price? maybe like 200 bucks.

Would i have to buy the headers separately at a different store or online or do you think a shop might sell them and install?

More air in, more air out equals more power. Even if you're never going to mod the engine (and certainly if you do), a complete exhaust is worth while. Whatever you do, purchase a Y pipe with the headers. Though pricey, I recommend the following direct-fit system (no cutting, bending, or modding of any kind):

Hooker 2055's (Jeg's 520-2055). Catco high-flow converter (Summit CTO-9118). Hooker catback (Summit HOK-16823HKR).

JamesC

How would it do without a cat?

Running without a cat doesn't gain that much horsepower and you are going to need a cat if you want to pass a sniffer test.

Getting headers is definitely worth it. I think hedman makes a pair of shorty headers for $170 or something like that... I ordered mine through summit online and had them the next morning through their overnight shipping. Installing them is not THAT hard to do. Any moderate do-it-yourselfer should be able to install them in less than a couple hours.

I run my Iroc with hedman headers, a y-pipe, no cat, and a flowmaster muffler. I would for sure get a y-pipe otherwise your flow gets pretty messed up and most places charge about $100 for a good y-pipe (including installation). I have heard that you gain about 5hp by eliminating your cat, that's nothing you can feel but it's worth it if you don't mind burning a little extra gas and you don't have to pass emissions testing. As for mufflers, everyone will tell you something different. Basically, you get what you pay for. If you buy a $100 flo-pro, like I did to hold me over for my flowmaster, don't expect much. Good luck.