In my stroker van on the street at light steady cruise even at highway speeds I can often see, believe it or not, 21hg, but on average about 18-19hg or so. As indicated by a SW panel mounted gauge. My idle vacuum is about 8-9hg in gear and about 11-12hg in park. This all matches a handheld vac gauge I have used before the gauge. If I used half of in park idle that’d be about a 6.5 but in gear a 5.5
The thing would never open until I really got into the throttle. There’d be nothing at all on the primaries under any amount of load until I got into the secondaries heavily. Nothing like feeling the power kick in even more from the PV with various light throttle only on the primaries.
Just like someone experiencing a tight higher stall converter for the first time it changes what you may have believed prior