headers questions?

hey..i have a 98 3000gt sohc..ive dont alot to my motor for it being sohc in my opinion anyways..i have the heads port and polished..cat back borla exhaust ( the vr4 cat back ), injen intake, msd ignition coil and spark plug wires, but i was looking in to getting the long headers for my car for much better flow out of the motor..cuz the rear exhaust manifold does like a flip in to a catalytic converter then down the the exhaust..but my question is..if i get long headers does that eliminate the EGR valve..would i have to get egr block off plates? that would be good anyways if it does get rid of the egr cuz my egr has a hole in it and makes an ugly "put put put put" when i accelerate..well let me know guys..thanks