An exhaust manifold for a 1955/56 265 V8 has an outlet that's forward of the position of the one on a rams' horn manifold, enough to clear the steering gear. Unless you're planning to do a lot of full throttle operation with a pretty radical camshaft, the slight advantage in exhaust flow volume of the rams' horns is going to be a moot point for normal street operation. Those manifolds are on Ebay pretty frequently, at reasonable prices. Ditto for swap meets.
www.ebay.com/itm/286506131038?Jerry
