LED tails are
not necessarily a "very good thing". It depends on whether they perform adequately, and many of them do not. To make a safe, good-performing LED lamp for an older vehicle application is not an impossible task by any means, but it is not a simple or trivial one. There are critical safety performance issues involved with a car's brake/tail/turn lights; they need to work in specific ways to do their job effectively and keep you safe on the road. Just looking at a homemade or aftermarket brake light and saying "Yup, looks nice and bright" isn't good enough. Before you spend much money or time on this, see
here and
here and (more technical stuff)
here. You might also want to look
here. See also
here and
here.