I installed a while ago in my SC a set of LED from Superbright. That was not bad for about $1.5 a bulb.
I also noticed a lot of postings about LED's which are much brighter then the SB once.
I did some testing to compare some of the bulbs out there.
Here is what I used.
No. 1 is the standard bulb which work with the dimmer.
No. 2 is the Superbright which is not bad, About $1.5 each, but they don't work with the dimmer.
No. 3 I found on Ebay Germany EUR 3.5o - these work with the dimmer
No. 4 New design with 3 small LED on top and 1 LED left and right. These work with the dimmer and light up the most difficult instrument, the clock, since it has the only one bulb on top.
Here is a picture with the clock and the Speedometer with the original bulbs.
This is with the Speedo with the SB LED and the clock with the standard bulb
Here an other angle
This is the LED from German ebay, the clock still on standard bulb.
This in the new LED set on the dimmer low
and here on dimmer high
Now this one is with the clock installed with the new LED.