Dot 3, 4, 5 or 5.1

[Dave Riddle <dave@microworks.net>]

One of our local Triumph Club members is just finishing a resto job on his 
TR3 and is pondering which brake fluid to go with. The system has been 
either replaced or completely flushed so there is no issue of going with DOT 5.

Which do you guys recommend? Or why "not" to use a particular fluid.

This is for a non-racing application.

Thanks!