Question about Dodge hubcaps

Tough to answer your question definitively. Describing spinners makes me think of wheel covers and not hubcaps though the terms are often used interchangeably. If you are referring to hubcaps specifically there are basically two sizes (diameters) used on passenger cars from early 60's to late 80's. Your '68 uses the smaller size. All the small size hubcaps are interchangeable regardless of year. A little research on this site will give you what those diameters are.