Several questions about cleaning...

What is the best method and material for cleaning the chrome on the bumpers, emblems, mirrors, etc. that will shine them up, protect them and not harm them? also I just got my first classic, a '66 c-code coupe, and I was wondering about steam cleaning the engine while its still in the car, can i just cover up the carb and distributor and steam clean everything or will that harm stuff? It has a bunch of built up gunk all over the place and I'd like clean before i start working on it.