I bought a used RK 421 header and I need to clean it up so I can put new gaskets on it when I install it. Besided just using carb cleaner to get the carbon off the flanges, what shoudl I do to clean them.
I was thinking maybe a scotch pad, but would it hurt to just get some 300 grit sand paper and a flat block and smooth them down? They are a little dinged up in a few places I figured that couldn't hurt it. Im talking more about the downpipe flanges than were it actually mates to the motor. Would it be a good idea to do that too?

Thats all id do because once you replace thee gaskets it should seal up pretty good.

If you have air tools a nice angle grinder with a sanding disk on it is great for things like this, and also great for cleaning up rotors for doing brake jobs also.

The flanges look like they are coated with the ceramic paint so Im not sure If I want to sand it down because of rust. I suppose it wont matter once I get the gaskets on good and tight.

yeah just sand em nice and flat and you'll be good to go






Brian