OK I appricate all the help everyones given me sofar but i have another question. how exactly do i install my header? just unscrew the bolts and re-attatch them to the new one? and should i clean the insides out of it, so practically gut the oil and crap out of there and if so what should i clean it with?
:scratch

gasket match the head to the header.. That would be my guess. cleaning crap out of stuff can never hurt.

what header did you get?

first take of your heat shield (EXTREME BISH), now make sure you disconnect your o2 sensor, then take off the stock header (eight bolts i beleive), now you will want to remove the gasket there and make sure no left over gasket is on the manifold), now take of your stock flex-pipe unbolt it from the cat. Now first place your gasket on, then put the header on and bolt header on (not 100% sure of torque specs) and do it in a zig-zag pattern. Now bolt the downpipe onto the header, then bolt the cat onto the flex-pipe and your set.....wait forgot the most important part TEST DRIVE & BUTT DYNO = ) have fun!