headers for a 318

Ready to put a dual exhaust on my 1975 dodge dart, engine is stock and has stock manifolds on it now. The big question is do i put headers on before i spend the money on the exhaust or just stick with the stock manifolds? I'm not looking for performance because i'm not building a racer, just a Sunday cruiser. If headers are what you would use, any ideas on a bolt on easy install set? ( no cutting, changing other things to make fit ) Any help would be greatly appreciated.
Thanks dan