www.amkproducts.com has similar if not the same 1/4"X 1" Bolt. I have seen a different head marking than Jack's above picture....so long as some G.M. headmark would be OK!
WELLNUT is/was brand of Valance nut of which AMK has on page 70 of catalog, but not sure if O.E.M. Washer useage appears to have been improvised at factory, as not captured or anything special
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Chuck Sharin
[email protected]
Auburn,WA (30 miles South of Seattle)
70 Camaro R/S Z-28, L-78, R/S SS
69 Camaro COPO "recreation"