I have pypes longtube headers and there looking extremely blotchy and blue and rusty looking in spots. I would like to know the best way if at all possible to clean them up a little
Try a "Scotch Bright" pad on them.
I use a green one on my JBA ceramic coated to get
the brown tarnish off them, works good, just a pita
to get hands in there.
If you have polished headers, may want to try the
fine ones they use for paint work.
Get some stuff called Blue Job. Call your local Harley dealer and they probably have it. If not you can order it online. I used it many times in the past and it works great.