GM used these coils on a pickup as well as the Corvette.  They were mounted on the valve cover.  I don’t know if the stock mounts would be of any interest.

If you have a friend that likes to machine aluminum, you can make one like this from a billet of 6061.  This, of course is for a 20B.  It bolts to the rotor housings, and the coils are held in place by allen-head screws (not installed in photo).

Al