Howdy All:
Havoline- The carb can be used by itself. It won't give you much more in the way of performance over a 1101.
The H/W 2 stage two barrel is a more sophisticated carb than an Autolite 1100/01. THe primary bore is smaller than the 1100/01. The secondary butterfly doesn't begin opening til about half throttle. It will require some fine tuning to get it right on a Ford Six. If better mileage, driveability and smoother idle are the goal then to that extent, it will likely be "more efficient".
The term "Efficient" may be confusing in this discussion. Relating to "VE" or volumetric efficiency, slade is right. Changing to a larger carb may not change the VE, as it has many factors that effect it. VE is typically calculated at WOT in an rpm range near the peak torque reading. Obviously, this will take into effect cam timing, head flow, compression ratio, exhaust, ignition and, of course intake. Simply changing to a larger carb will not have much effect on VE.
Dan- Yes, for economy the two stage 2 barrel design should be better for economy. The smaller venturi should create higher vacuum and more velocity, creating a better mixture. A well tuned 5200 might give you a 10% increase in cruise mileage under ideal conditions. So if you're getting 20 mpg, you might see 22 mpg. This is assuming an optimized ignition system too.
realistically, you should be able to get that much of an increase in mileage by optimizing all the systems that you presently have, and follow Slades advice and drive as if your go pedal foot was a raw egg and if it breaks you have to clean up the mess.
Adios, David
