I was wondering if the headlight surrounding on a '74.5 260z is interchangable with the later model s130 280zx. I believe the later model ZX changed from a metal surround to a plastic. Should that make a difference in the way it fits?

Not the same. You can use one from any '70 through '78 Z (240/260/280) but not from the ZXs. The early 240s had plastic, the later 240s and all 260/280Zs had metal. But they all interchange through '78.

The later 280zx is not interchangeable with the early z cars. It is a completely different shape. ie more squared instead of round.

Thanks a lot guys!