My first Mustang was a '66 convertible with a 200 cube, 6 cyl. I was servicing copying machines, and I put 75,000 miles on the car in 3 years! Drove the you know what outta the car. All I did was change oil every 2 - 3 k miles.
I had a friend that ran an irrigation company in Neb. They used 200 cube Ford engines to run the irrigation pumps. Those engines sat out in fields for years. The lucky engines had a simple corrugated tin cover over them. My friend used one of those irrigation engines in his 66 Mustang! They are a tough old engine.
have fun, Dave