Cast iron exhaust manifold cleaning

The POR stuff rocks! it looks like crap until you start the engine, then it melts into the manifold, all the brush strokes go away. But the best part is touching them up with a small brush - start the engine and the touch ups melt into the existing paint and you can't even find the repairs - sure beats taking the manifolds off to re-spray or spending hours taping things up to respray in the car...