No, you can't directly put a 1969 Camaro body on a 1999 frame. The chassis and body dimensions are vastly different. The 1969 Camaro uses a unibody-style construction (although a fairly basic one compared to later cars), while a 1999 car likely has a more modern separate frame and unibody construction. The wheelbases, suspension mounting points, engine bay dimensions, and overall body structure are incompatible.
To achieve something similar, you'd need a significant custom fabrication project involving extensive modifications to both the chassis and the body. This is a complex and very expensive undertaking requiring significant welding, metalwork skills, and engineering knowledge. It's not a simple bolt-on swap.
