Brickman: The frame is of my own design, as is the one under my coupe. Chassis design and fabrication is one of my favorite parts of building hotrods. There are at least 18 or 19 of my one-off frames running around under various street rods. All of them are built from rectangular tubing. That's why I wanted to do one from round tubing - something different and a new challenge for me.
EG: You are correct... up to a point. Any type of dipping (like galvanizing) or plating process can cause nitrogen embrittlement of the base metal and therefore cause big problems related to metal fatigue, crystalized welds, etc. You can use galvanized in a non-stress area, but I would not use it on the chassis, especially any part of the suspension or steering.