I haven't done much searching, so let me apologize first...

However, what sort of tricks do 930 guys (and gals) do when rebuilding their engine so that it retains its stock appearance, feel, etc., but with a little something extra?

 

Well all air cooled Porsche motors really all look the same when you strip them down to the long block. So by "stock appearance" do you mean something like an intercooler or exhaust? Your post is vague so why don't you tell us what your goals are and then I can help.