Along that line of thinking. I thought machining a counter bored hole in the spacer for an allen head bolt to allow screwing it to a matching threaded hole in the intake manifold. Then whenever the engine is taken apart, you just leave the intake and the spacers screwed together. And the final hand porting is done with the spacer screwed to the intake for a perfect match. The blue holes are what I am thinking. It doesn't need big allen head bolts, maybe 1/4", since the clamping is done by the original 3/8" intake bolts. Just enough to keep it together in the same location.