My opinion would be to stay away from the 39 tear drops. My experience with them in a Mullins trailer and on a 39 Ford, is that they have to be mounted perpendicular to the road other wise they will be hard to see from behind. (and really so if you use blue dots). The new LED ones are much brighter but again they shouldn't be mounted on an angle (LED's are directional lights). 39 teardrops are really cool, but I prefer being seen from behind and at a distance of more than 20 feet.

The tail lights of a 55 should be work really well for you. They have LED's for them as well.