GM p/n 11501105 (Listed as M6.3 x 1 x 20). There are no phosphate M6.3 x 1 x 25 in this style of bolt in GM's parts bins that I can find, so I'm imagining the 25 length is aftermarket. Probably won't make any difference.
Auveco equivalent is 11633
Hmm. Lowe's home improvement store sells the 25mm under Hillman brand. 1.54 for pack of 2.
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