I have twin FlowMaster 40's on my 72 Fury III. It has stock exhaust manifolds but I did change the cam and put a 4 barrel on it. Then I bought a 4 barrel Air filter housing and put 360 4 Barrel stickers on it to make it look stock (360 only came 2 barrel). It sounds awesome thru the stainless steel exhaust and the 40's.