First of all I am hoping the part of the thread about Karol Miller that ended up about air pressure and flow can be moved here so that everybody can find it again.
"Re Doug, Would seem as though the inertia of the air would have more effect than the formula gives. What am I missing? Pegleg"
Well that is a hard question to answer 
. Seriously I think it might be the preception that when you stick your hand out a window of a car going say 100 mph it generates a lot of force. of course the pressure isn't high but the area that it is acting on is more than you might think. Also there is the aerodynamic drag acting on your hand that we haven't considered in any of this discussion.
Charlie
I think that the idea of sourcing the air for the carb from the base of the windshield is the way to go because most of the relevant experience seems to say that this is the highest pressure area that you can find. Also doesn't your truck have sort of a visor over the windshield? This is likely to increase pressure at the base of the windshield even more.
You might be able to get an accurate reading in the carb bonnet with a sloping tube manometer mounted across the direction of travel so acceleration doesn't effect it. I think the only way to read it safely would be to video it while you do the driving!
The idea of smaller openings in forward facing hood scoops it likely correct because strictly speaking the small opening allows for what is called "Static Regain" by allowing the air to slow down and convert its dynamic pressure into static pressure. So as long as the air velocity through the carb venturi's is much higher than the velocity through the scoop's hole there will be efficient static regain. BTW I hope everyone notices that Ted Eaton's hood scope meets all these criteria. For a discussion of static regain look in a New York Blower book which discusses this topic a part of the discharge velocity of industrial fans.
Finally sloping tube manometers are easy to make with clear plastic tubing. If you have a rise:run ratio of say 1:4 then 1/2" movement of the water along the slope will be 1/8"wg which is a pretty low pressure!
Doug T
The Highlands, Louisville, Ky.
