Headers & Cam upgrade or Rear Gears

Hi,

New to the site looking for some advice on performance upgrades on my 72 Duster 340 . The car is all stock 70K original mile survivor 340 904 8 3/4 3:23 SG 225/70/14 tires stock converter Edelbrock 600 carb stock CI intake stock exhaust manifolds . On the fence if I should do a cam swap and headers or just upgrade the rear gears to 3:73’s or 3:91’s ? The car will be 100 % street car and very little highway use . Just looking for more seat of the pants fun light to light . I’m not looking to change the converter from stock . I think the least expensive option would be a rear gear swap just wanted to know if I would feel that much of a difference from the 3:23’s