I used to have the exact same problem with my 67 Coronet. Before I did anything I adjusted the hood latch assembly so that I had to shut my hood a little harder (a soft slam) to close it and that did the trick. It's been about 4 years since I've had it happen.
I used to be able to shut my hood without slamming it. I would just close it and then press it down with my hands and it would latch. But if I hit a bump at highway speeds it would pop open to the secondary latch. Only happened twice but it was very scary when it happened.
That's exactly how I have mine set up, just push to shut - I'll try lowering my latch to a "soft slam" point and see how it works for me on the loop highway in town. Thanks for the tip!!
1967 Dodge Coronet Deluxe station wagon
1.03" T-bars, QA1 arms/rods, Cordoba/GM Metric/Volare brake & knuckle, XHDs, Hellwig rear sway, 318 Magnum w/ air gap, 727, 3.23s
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