I had nothing but trouble with dot 5 in my '38. Brand new Wagner wheel cylinders gave up the ghost in 5 years (taking out my brake shoes with it of course) and stoplight swithces didn't last very long. Not to mention the extra cost of replacing the fluid everytime I repaired a leaking component. I went back to dot 3 and will try to remember to change it every other year.

One who knows that enough is enough will always have enough. Lao Tzu