classic motorcycle forum

It seems to me I read a post on this forum stating that in 1966 the rocker arm lubrication for triumph Bonneville's was supplied by a line form the top of the oil tank as opposed to a connection from a tee off of the return line at the base of the oil tank. The author also indicated this design lasted only a year as the design proved to be unacceptable. He also recommended replacing the upper lubricating tank with the later (maybe earlier?) model with the tee from the bottom. Anybody familiar with this issue?