340 exhaust manifold vs stock 318

Actually headers make a hell of a difference, but if you want a nice bump without the hassle of adding more engine heat and blowing out header gaskets and the head ache install of them, the 340 and magnum manifolds are for ya.
Yes I was looking at some shortys but as the link that forphorty posted suggests that the shortys are only good for maybe an extra 5 hp over 340 exhaust manifolds. I had a 74 challenger back in 1999 and I had headers on it but the very first bump I crushed the bottom of the headers (long tube) due to terrible ground clearance. I am building a 325 to 400HP max, motor. So with that in mind I think some decent manifolds will be much nicer for my application. But who knows the final project always looks a little diferent than original plans.