Carefully check all of the above, as any one could be a culprit on that age rig. Shocks especially. For me, in our second small "A" gasser, some roll is normal. I do find that 70 is a bit fast for it, and stability seems to be a lot less when we pass 65. (speed and age). The important thing is sway that affects your steering, causing swerving side to side. We do have some roll, but it does not effect steering or tracking, such as when being passed. I do get a lot of bother from gusty sidewinds, but have learned what to expect and what to watch out for.