I prefer the aluminum side and valve cover cause they seal much better and (to my opinion) look way cooler but this is a personal taste issue.

Here is what you are looking for:

Here , here , here ,
and here

those are only the first 4 of about 3 dozend I found. \:D

Go to Ebay and copy/paste exactly(!) this in the search box:
(chevrolet,chevy) (235,261)

or try this

Frank

To old to die young.