I ran the same tests with my race 470 and saw similar results. The annular boosters work really well in cold weather. Not that that matters much for a race engine but the difference in torque can be significant. Just has to do with how well the booster shears the fuel. I don't know if any of this would matter in your application or not. You would have to test it to find out. The carb I used on my 470 was a Quick Fuel 1050-AN. Out of all the carbs I tested it worked the best on the dyno. I never used that carb in a car so I don't know how it drove.
