Hemi Swapping a perfectly good 70 Duster

How did you smooth the intake? Did you also paint it? If so, what did you use? It looks way better than stock.
There was a bunch of plastic casting flash and other random things on it. I just sanded them off with a die grinder with a roloc disc and did some final smoothing on those spots with some plastic filler. Valve covers, and intake are painted with Cerakote.