Re: 1970 cowl induction flapper door
This dosen't immediately help your problem, but I would highly recommend buying a factory Assembly Manual for your car.
It will give you detail to the nut, bolt and washer on this, and every other question that you will likely have.
The first thing I do when I buy a car is buy an Assembly and Service Manual.
These are a must have.
You can likely contact your parts supplier tomorrow morning, tell them what your dilema is, and a good sales rep should be able to send you anything that's missing, and your new Assembly manual to help you solve this, and many other future questions regarding correct assembly details for your car.