I am not seeing the unusual drive shaft. All of the 1/2 ton & 3/4 ton 4x4 drive shafts were made like the one shown in your photos, as standard equipment. It may be 7" around, but it is not 7" in diameter.

Tony Smith
4-5-6 Chevy Trucks
501 Scott Avenue
Kansas City, KS 66105
913-207-7789
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Custom Parts: http://www.flickr.com/photos/4-5-6chevytrucks/sets/72157627022818563/
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