>>The reason GM and Summit state to use ported is for legality/SMOG green tree hugger reasons.<<
That simply is not a true statement. GM used ported vacuum long before they started with the serious smog systems.
PCV System was the first smog system used on automobiles and it was used to replace road draft tubes.
Early 50s 235 six with Rochester B. The two metal lines to the carb are fuel and vacuum advance line connected to ported vacuum next to mixture screw.
Here is a mid '50s 283 with 2GC and again ported vacuum.
From your link in jalopyjournal.
>>The number one main reason you want full time vacuum is that you need to run a considerable amount of advance at idle.<<
need to run a considerable amount of advance at idle ? What need?
>>Running the engine at idle without the extra advance provided by the vacuum advance system will have the engine running hot in almost all cases.<<
I guess lack of air flow through the radiator at idle has nothing to do if whether an engine heats up or not at idle?
>>engine needs quite a bit of advance at idle since the fuel/air mixture is lean and it takes longer to burn the mix at a low engine rpm<<
If I was worried(?) about a lean mixture taking longer to burn at idle, I'd just turn the mixture screws out a little.
He goes on to mention that manifold vacuum provides
Vacuum Retard, but only in reference to engine cranking conditions. He needs to take a closer look at cranking rpm, low vacuum during cranking and the simple fact that ported vacuum would provide 0"Hg and 0* advance while cranking.