Biggest difference in 2004 presidential result in bordering counties

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With a quick glance, below appears likely, though I haven't verified it. Anyone know for sure?

Macon, AL 82.9%-16.7% Kerry
Elmore, AL 76.9%-22.6% Bush

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Shannon County, SD:  84.62% Kerry
Sheridan County, NE:  82.19% Bush

Of course, that is explained by Natives on the reservation, though Sheridan is actually 11% Native.

A follow-up question would be "what is the biggest difference in 2004 presidential result in bordering white-majority counties"?

That appears to be (below), though I am not certain.

San Miguel, CO 71.56% for Kerry
Montrose, CO 69.17% for Bush

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I decided to look up the biggest differences between bordering counties, with each having at least 100,000 votes. These appear to be the largest (please correct me if I am missing any):

DeKalb/Gwinnett, GA 78.25
Prince George's/Anne Arundel, MD 76.85
Los Angeles/Kern, CA 61.50
Cook/McHenry, IL 61.48
Broward/Collier, FL 60.48
Milwaukee/Waukesha, WI 59.62