I'm going to install a dual downpipe manifold on a B20b. I plan to replace the manifold studs with new studs. How to I get the old studs out? What is a good torque number for the manifold 15- 20 lbs? How to clean up the carbon and rust on the manifold? How about a carb cleaner bath? Should I worry about the thickness of the casting if I wire brush/flapwheel the pitting on the casting to smooth it out and dress it up before painting? Thanks for the help from someone at the front end of the experience curve. Bill