Topic: Fender Bolt Head Markings for a Feb/March 66 built GT350

[Bob Gaines]

It would be safe to assume these bolts are aftermarket that are currently holding the hinges on correct? Never seen this head marking

That bolt is not original to holding the hinges on or any other place (with those markings) on your GT350.

[jwc66k]

That head marking does not appear in any AMK hardware for Ford or other car manufacturers (for at least 5/16 and 3/8 bolts). I describe it as the letter M in a hexagon and it's a grade 5.1, which was not used in 1966. However, it's a Shelby, and they were interested in selling race cars, not concourse grade cars, so who knows.
My advice, either throw it away, or put it back on your old beer 'frige.
Jim

[Bob Gaines]

I vote for throw it away so it doesn't get mixed in with Mustang/Shelby assemblyline bolts . The correct bolt once installed at SJ would not be one that SA would be fiddling with. The hinge was installed at Ford. After the hood was added at SA two bolts added at the hood and hinge adjusted .

[J_Speegle]

It would be safe to assume these bolts are aftermarket that are currently holding the hinges on correct? Never seen this head marking

Yes you would be correct