A side note re the stainless... when I switched to stainless, with the whole run to the water mufflers on the Beast (gasoline engine) the noise went up dramatically. I'd had rubber hoses after the risers and with the new risers, well, they were taller with an exit direct aft versus downward slant.
Of course the old hose didn't fit. Thus stainless. And a lot more noise.
Nothing to offer re the specific question... just throwing this out as an aside.