Vacuum advance sbc

I read an article that said you should run full vac advance at idle, if this is so don't most engines {mid to high lift cams} make very little vac at idle therefore the 15"hg needed to open a stock can isn't present. This article was written by a GM engineer on the Extreme Chevy site, he even gives a Napa p/n for a can that will open with 8"hg instead of the normal 15" hg. I checked and its not available. This article was on a couple other sites also. Any thoughts on this?  
41 chevy

I have read it and it makes sense to me. You would just need to see if the idle vacuum your engine was making was enough to operate the advance unit. My engine has a fairly stout cam and a MSD pro billet distributor. The advance works fine.  
Jim
70 El Camino
461 solid, m20,
pics in readers rides

I agee with what this guy says also, but i only make 8"hg at 900rpm. i'd like to find this advance he talks about that pulls in full degree advance at 8", like i mention earlier most stock need 15" to pull in completely  
41 chevy