Was wondering about a exhaust upgrade for my engines. I was considering the alm 496 manifolds, would there be any trq. or hp gain over stock iron manifolds? I have 496(stroked 454) dart pro 1 310cc alm.heads edelbrock rpm intake,hyd.roller, 750 marine demons with merc. stock wet exhaust with accesseries it dynoed at 600 trq 500 hp. Should I consider aftermarket , or the 496s and what should I expect to gain? Also if I was to upgrade to a bigger ci or blowers later which would be still ok full blown headers wont be in the bugget at 10grand .thanks