I just converted my interior dash and HVAC controls to blue LEDs. The bulbs are #74 and I got them from superbrightleds.com. They have an inverted tip that makes them disperse light better for a wider beam (think flashlight as opposed to laser). I haven't added any extra bulbs, just replaced the stock bulbs, but the light is pretty spread out.
I'll find a way to make the fuel/tach needles brighter, but other than that, they came out looking good.