Thanks, Steve. I've got a 304 stainless bend that I'll be welding to the manifold, & could have sworn that I read online to use 308L rod for stainless to mild steel, but I can only find one reference now, & it's on a welding forum where someone says it's 'ok'. I'll try to find some 309L or some 347 when I go to the welding shop this week.
Charlie