Ok, I customized my own exhaust all the way to the y pipe, then from there to the tips, its straight back. The only thing i did not mess with is the header, i left it right where it was, is this messing with me? Is it a restriction, or do they flow just as good as aftermarket, if they don't, where can i get some hood ones, but not too expensive, let me know.

 

If you have a header, then you should be good to go. If you have the stock exhaust manifold, then you would benefit from an aftermarket header.

A manifold and header are different.