Maybe my issue isn't so much with the crossover as you all seem to think. In Nitrousn's explanation, he commented about the choke operation as did Runcharger and his comment about if the choke is even operational. Well, the choke is fully operational and when the engine warms up the choke fully opens. I'm not saying that the passage might not be plugged as suggested. I'm just saying that maybe this isn't the absolute cure for my problem.

I would also point out that not too long ago another member posted about a hesitation/bog with his 318 equipped with the same Holley 2280 2bbl I have and no one told him his passage was plugged. Turns out his problem was the power piston and I had asked for more specifics but never got an answer. EVERY 318 I've ever owned, either with the Carter BBD or this Holley has always has this same bog. I've just learned to drive with it. I know my main question with this thread was about increasing fuel mileage, but in this case I think the two may be related. If my power piston was stuck in an enriched position, could it cause the hesitation and also allow it to run rich at cruise, reducing mileage? Also, I don't think the mileage with this truck is too far off average. I'd say about 10 or so around town and about 14 on the highway. I was just looking for a way to improve on that if possible.