What about cutting a couple of aluminum bosses off of a "donor" intake and having them tig welded to the LD4B in the stock location?
We replaced an edelbrock performer and holley intake for a LD4B and edelbrock carb with electric choke and it ran great. Stock 71 318 2 bbl engine with a 4 bbl and dual exhaust. It ran great off the line with no hesitation. Much better than the performer.
I would be worried about mounting the coil off the carb base studs, as the vibration may cause the carb to leak in the long run.