The simple answer is, all of them. Mine is a 69, not sure what you have, but I think all 67-69 function the same. Three lights for each side and they all should light up for brakes, lights and turns. The original sequencer is very problematic, so if you can, you should try to find a electronic replacement. There may be other places, but here is one I've used
Cougars Unlimited Home Page.
Much better system, but it's not cheap. I replaced the electronic sequencer, but the directional relay malfunctions for left turns. It needs replaced as well, but I'm not willing to spend the extra $100 right now.