I don't normally post "told you so" responses, but for this one, I could not resist. Seems the problem was indeed in the suspension and not the wheels/tires. Just like a modern BMW
In about an hour, I am headed off to the tire shop to have the wheels/tires on my new to me '71. This truck shakes the crud out of the front end at about 65 mph. Sometimes worse than other times. I suspect worn out suspension components are to blame. But, IMHO, always a good idea to start with the simplest of possibilities...the wheels/tires. We'll see.
