I just completed a really cool upgrade modification to the brake/turn lights on my 66. I updated them to real LED lights. Not the cheap 1157 led bulb. I used a 2 way 16 LED "Truck-Lite" LED pack part # 21271R. I then cut the light housing open to get the light pack out and it fits perfectly in the original tail light housing on my 66. The led light pack measures 1 1/2" x 3". The only thing I had to do is run a ground wire, because the bulb socket housing is the ground on the old bulbs. I used bullet type connectors, because that is what was already on the LED light. They are a lot brighter and a lot safer than the old 1157 bulb. LED's also light faster and have a longer life to them. I spent about $80 for the upgrade and it looks and functions much better than before. I will try to post a pic soon.