I recently bought a 1979 280ZX and have my first stupid question. I wanted to replace the hubcaps (one of the few bad design elements on that car). I bought a set of 280Z hubcaps in the same wheel size (14"), but I can't seem to get them to fit. They sort of wedge on but I can't get the clamps pounded in evenly all around. I also noticed the cutout for the valve stem was positioned differently in relation to the cutouts for the lugs. Is this just a no go? Can you not interchange those caps even though the wheels are the same size?