I put the line on my TR3 along with the aluminum rocker spacers. It quieted my valvetrain down considerably, but at a long traffic light, or other extended idle, the car would load up from the oil getting past the valves. Had to rev the engine occasionally to keep it clear or it would misfire when I took off.
I later installed a NOS Lucas electronic ignition update kit with a different coil and a trigger box on the fender. (Can't remember what they called it) Still uses the points, but reduces the voltage through them. Spark gap got increased to .045", and now it can idle all day with no fouling.