At 40-45 mph around town you are most likely into the main circuit. When you are in the main circuit the PV is a factor if your vacuum drops low enough for enrichment. Cruising with a vacuum guage inside helps add a afr guage and your really cookin.
I thought that was possible as well, but I really don't think I am where the AFR shows 10's.
I also have a ,67 to one overdrive, so take that into account.
In 3rd I would agree at 40-45 I would probably be in the mains.
PV is a 6.5 if I didn't answer that yet
Manifold vacuum at 800 idle is 14.
I can get a vacuum hose for my gauge to reach my wiper arm.:D
Probably over it for tonight, but thank you.
Ah crap I forgot to mention I'm normally in OD at 40-45 with 3.55 gears so it takes very little throttle. (I'm the dumbass this time) :D
I'd bet I could put a round toothpick under my idle screw and do 40-45 in OD.