Hey there Stangman,
 I just based my thoughts on the performance and longevity aspect.  Thinking of when opening up the carb quickly with a smaller motor and a big plenum, there would be a considerable power bog at the start.  I know this could be compensated for some with a more aggressive accelerator cam.  Or a larger pump, but that could wash the cylinders more and could be a problem sooner than later.  To be clear as I can on that thought, I’m not saying in a thousand miles the combo would ruin the engine!  But it could shorten the life by 20,000 to 40,000 miles in comparison, in a longevity consideration.
I’m just keeping the conversation going for us to think about thus stuff.  And in all fairness, Jay’s book stated the most power a 390 made was with an old school Streetmaster with plenum work and a 1” open spacer.  That is an argument itself with my F-427 theory if you think about it…. That all said, the Streetmaster intake will not look original(!!) , and does not have the PCV hook-up provision.
                                                       Mike