Not "special" so-to-speak, there is only two different style of instrument sockets for the 194 bulbs. One is 5/8" and the other is 1/2" if I remember correctly. One is Dodge style and the other is Ford style. Pretty sure the Dodge was the bigger one. Which ever socket superbrightleds offers with the bulbs is the one that worked for mine. Because the Ford bulbs are not soldered in from the factory like Dodges are so they're not commonly seen unless specified.
Dimmer doesn't work with the LEDs, but nothing a simple resistor couldn't fix in the dimmer switch. As these bulbs are also internally resisted for dimming. But Dodge dimmers don't have a very good resistor factory. And these put out a good solid color without being blinding or needing dimming. But my gauge faces are black.