Need help and info to help out my autistic son with his project

There are a couple of other options you may or may not have thought of. First you can go with tubular K-frame and coil over front suspension. This would eliminate the torsion bars which will help tremendously with header room. Second is to use a straight axle front suspension set up which will really open up the header possibilities.
I have a friend of mind who did something similar with a 65 Falcon with a 427 FE engine. He went with the straight axle and the headers were simple.