Started working on creating an ALL Generation LED bulb guide. Also we will include HIDs to make everyones life a little easier. If you have read through a bulb replacement guide you will notice that most of the LEDs bulb # is the same as the halogen bulb number say from PepBoys or Autozone. Here is a good link also to try and figure out what sort of bulbs you need for ANY vehicle. They way they create their list can be slightly confusing though, Superbright LEDs. A little more on reading into LEDs as well reveals that most suppliers label their LEDs the same way. We will use the most popular "921" bulb The p/n for a blue 921 as seen in the pictures below is, 921-B12: 921 <--refers to the bulb type B <-- refers to the color 12 <-- refers to the amount of LEDs in the bulb another example would be a red version for the third brake light which would read: 921-R12 Also remember LEDs are polarized, meaning they will only work one way. If you plug your brand new LED in and it doesn't work, pull it out and insert it the other way before making an angry phone call to the supplier! 4th Gen LEDs Reverse - 921 Cargo Lights/Top mount break light - 921 Map lights - 921 Dome light - 4410 License plate - 194 Tail lights / Brake lights- 3157 Front turn signal / Side marker - 3157 4th Gen HIDs Quad lights High beams - 9005/HB3 Low beams - H11 Dual lights High/Low - H13/9008 Fog lights (regardless of headlights) H10/9145/9140 THIRD GEN LEDS Reverse - 3rd Gens from 02-06 use 3057/3157, 07-08 use 921 Third Brake Light-921 Dome Light/Map Lights-578/212-2 (I found one that is MUCH brighter that fits both festoon style map lights and the dome light, it is a 4210-HP6 bulb, I used 'cool white', so as described above a '4210-CWHP6' bulb. It's like daylight in the cab.) *Note* Some trucks also have the map light bulb listed as a 194.* License Plate-168 Tail Lights/Brake Lights-3157 *Use a RED bulb for this* Front Turn Signal-3157 INSTRUMENT CLUSTERS Speedometer/gauge cluster-B8.5 (Will update with additional bulbs, HVAC, overhead console, ect) Also, many of the miniature wedge base bulbs (921, 194, 168,) can often interchange, allowing you to use a brighter bulb, IF it will fit in the lens as far as the dimensions go concerning height, width, etc... Here's another source for LED bulbs, resistor packs, etc...that does very well with their quality and customer service: AutoLumination The website is a bit hard to follow but if you have questions, their phone customer service is pretty good. If anyone wants to cross reference the 2nd gen bulbs, be my guest! I'll add it if it becomes available.