He is building on a stretched Fiero though, and his body is made to fit on a Fiero chassis. To get the proper body to chassis mount, all he has to do is set the body on the chassis and see if it sits on the front frame (under the front hood) and the rear firewall where the back window is. The body was made to sit on these 2 points, all the other bracing is done once this is achieved.
Look inside the front hood area (front trunk) and where the body goes down into the trunk, there will be a fiberglass flange which is part of the body which runs horizontal to the ground. iIt runs on each side of the front trunk, and in the front just behind the front bumper. This horizontal flange sits right on top of the Fiero chassis, and this is where thr front part of the body bolts to the chassis. On a Fiero, the front frame needs to be extended about 1 foot, and then linked together with another piece of steel (square) tube. This link piece should be located directly under the front bumper flange, and is where the bumper bolts to the chassis as well. Since the G kits are unibodies, the front bumper is part of the fenders, meaning it was cast as one piece instead of separate fenders and bumper. This makes it easier to bolt the whole front of the car down to the frame, and is very rigid when completed. It also makes mounting the body to the chassis to achieve the proper height dummy proof.
In the rear of the car, the area under the bat wings should sit directly on top of the sheet metal that composes the strut towers. Once this is accomplished, the rear window area should be sitting directly on top of the rear Fiero firewall, and should be bolted down to that as well.
Once all of this is accomplished, you can then fabricate your rocker supports, and interior sheet metal fill-in's between the Fiero tub and fiberglass body.
