I have a machine shop, so I could just build 12 pieces that would just cover those holes, or thread them when I remove the intakes, which I will be doing anyway. On another note, I think I could still use that smog pump to run a vortex cooler for the fuel line. I trashed the fuel cooler that runs through the A/C line when removing the A/C compressor, which only runs when A/C is running anyway.

 

or find a set of Euro.spec intake manifolds, up to 1980 they had no holes, they were blank.