I got a 2012 Ram Express with the stock dual exhaust and I was wanting to know if there was any exhaust MANIFOLDS (not full systems) that I could easily install on my truck that would give it that throaty, muscle car like sound. And preferably one for under $300. Thanks.
I know that you capitalized the word manifolds but I do believe you are still mistaken in what you are looking for. Shorty/LT headers (the "manifold") will not give you a more throaty sounding exhaust with just the factory exhaust.
You want to look into a new exhaust system to replace your stock muffler and/or resonators. Mufflex and Boesch Built both offer a quality bolt in Magnaflow solution as well as Flowmaster now. Or you can look into many cat-backs that are available.
You dont get any extra sound from a header unless you already have an exhaust system or muffler. However, headers are a good choice if you are looking for a good performance gain later on down the road.