My dad was the original owner on my 1979 280zx. For some reason when he bought it he told the dealer he didn't like the mags and told them to just put stock wheels on it.

I currently have 195/70 R14 tires on the car. I'd like to replace both the wheels and tires, but haven't really decided on what size rims to go with.

Is there any reason other than personal choice it would be better to go up to a larger size rim?

No. It's totally up to you.

thanks