Use a left side exhaust manifold from a 55-57 265 engine. They're available on Ebay frequently for very low prices. It has a front outlet and is made to clear the steering gear. Using ANY kind of header except equal-length tubes from each exhaust port is foolish and does nothing for performance at engine speeds where street-driven engines run. 30-something years of dyno runs we did while building round track engines proved that to me repeatedly.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!