I'd dispose of that ugly scrap iron and go back to a regular exhaust manifold. Even with a properly designed equal tube length custom header, there won't be any HP or torque advantage at any RPM range a street engine runs on a routine basis. Even the cast iron replica Fenton "headers" are only useful as eye candy at a show and shine- - - - -there's no measureable gain in power.
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!