Being the cheapa$$ that I am, I would spend a couple hours in the shop and build my own. All it would take is a piece of 1/4 inch plate, a package of jigsaw or sawzall blades and a hand full of machine screws.
You could just use a valve cover as a pattern to trace the shape onto the steel. Cut out the desired shape leaving room for the double holes. Drill and counter sink the 1/4 inch holes that will hold the newly made spacer to the head. Drill and tap the narrow holes for the old style covers for 1/4 inch cap screws. Use flat head machine screws to hold the spacer down and install the valve covers with 1/4 inch x 1/2 inch long cap screws. I think 1/2 inch would work with valve cover hold downs. Of course it will take two pairs of gaskets.
I have never seen any of the adapters, but I can not imagine them being much different that the above.
Edit: After some more thought, I think that you could permanently install the spacers with RTV silicon which would make them less noticable.
Last edited by TurboS10; 02-10-2004 at 08:47 AM.