I've changed every bulb in my '85 300D to LED, with the exception of...

• Headlights*
• Fog Lights**
• High Beam Indicator light at Instrument Cluster

*Headlights have been converted from sealed beam to a 9007 halogen.
**When my factory sealed beam Bosch amber lights go out, I'll change them to LED as well.

The blinker LEDs required load resistors on each light to work right. Without the load resistors 1 LED blinker causes 'hyper-flash', changing both stops flashing altogether.

I put the regular bulb back into the High Beam Indicator on the dash because the LED was just way too bright.

I would highly recommend the conversion to LEDs on the Instrument Cluster, you know how dull the guage lights are and I could barely see the Glow Plug light during the day - not anymore.