You are inside of a thread where everyone on here is going to to post pictures and motor combos on their A body big block cars. My a Demon has nothing to do with your build. I would make the following recommendations..
1. Address the cars brakes. If you did not upgrade them, you may want to, the little drums on that car will make it hard to stop.
2. Upgrade the rear end. If your car has a 7 1/4 rear it won't last.
3. Address the suspension. Depending on how you build the motor you are going to add weight to the car's front. A heavy nose, light ***, and stock suspension is asking for trouble controlling the car.
4. Find Schumacher industries website. The sell everything you will need and have step by step articles. Michael is a very responsive and super helpful.
5. Build a 383. They grow on trees and the height of the deck will make it easier to close the hood and still use a nice dual plane intake.
6. Start another thread outside of this one in either Member Restorations or A Body Big Block tech, but avoid responding in this thread since it is not really for what you are asking.
7. I am going to PRivate Message you a test. It will give you an alert, then you can see how folks talk on here outside of the threads.
8. Tell your son to take a deep breath and relax. This hobby is time consuming, expensive, and at times it can be frustrating. You will get it there.