shorty headers for A Body???

Just broke down a 440, the engine came in a 73 dart, some body cobbled this together with whatever they had. Not to say I have never been there before. The engine was balanced, a set of 452,s cut way down, a purple cam#960002 stamped on end of rear journal I cant seem to find specs for the cam. The pistons were installed upside down, the front arrows pointing to the bell housing. Piston # L 2355 .040 over. Why? I don't think the gain here would be enough to even do this. I thought I would put this subject out there to chew on. This engine will be a weekend driver, with a sonoramic setup on top. had to cut the right fenderwell for a fit. used an O Riely alterkation kit in the front, wilwood brakes. Flaming river rack an pinion. I am looking for sum cast exhaust manifolds, the factory ones are beyond my price range. The hi po factory ones are to tall they hit the left side ram. So now I need a recommendation for an exhaust manifold. There lots of them out there.
Thanks
Hogranch