I think some of the diesel lorry ones would look nice
Or one off an old 2nd world war plane, they were all supercharged.
here's one , my Grandfather used to work on the Merlin engine at Rolls Royce , shame he's still not aroung he could have given you a few tips on how to fit this in the Zed engine compartment
Thats the one Tim , similar thing on the Messerschmitt 109................would need a bit of a bonnet bulge though