I think that someone else has made this point before. You can get a much more 'consistant' performance from the carburettor if you can control the temperature of the air that is passing through it & it's very likely that the stock air filter housing with the vacuum controled hot air/cold air flapper valve is your best friend.

It has a thermo vacuum valve inside & when the air temp is below the pre set value, the valve sends vacuum to the servo & it shuts off the cold air inlet, allowing only heated air to be drawn in. If the temp rises above that pre set value, then it opens the flapper valve & admits cold air.
I believe [but don't quote me] that it is capable of maintaining a balance of hot & cold air to maintain a constant air temperature into the carb. If this is true, then you couldn't ask for more. The carb can then be tuned for optimum efficiency & it will maintain that efficiency for as long as the engine is running once it has warmed up a little.

As that well known drag racer, Smokey Unick often said, ... "bring your variables under control" Wise words to remember.

I see a target of 100 miles [160Km] per Imperial gallon [4.54609 Litres] as being within reach.