I just bought an 84z, and it uses a pin downed hood. The hood simply wont stay down when accelerating fast. If I just cruise it will be fine, but when I stamp on it and the air start to flow it try to blow off. It used locks when I first got it and one of the locks broke when it started vibrating from air flow. My question is what can I do to stop it.

I've tightened all the bolts, didn't work. I loaded it with washers to hold it still and even it out to the holes, improved it but still no work. For normal driving it fine, but when I 1/4 mile it crosses at over 100 mph, and at about 90 is when it starts. Any help will be appreciated, thanks ahead of time.