Seriously, don't make a decision to drive the truck until you can climb under and over the whole thing first. Ask lots of questions, check the fluids, etc. While under truck, check for the obvious and spend some time looking around (lots of room under there). Check the back of the wheels for signs of leaks to the brake system. Lots of oil dripping? Smokin' out the tailpipe? Pump the brake and hold pressure on it, you know, stuff like that. Believe what your sense of smell tells you. Warm the truck up and drive it around the neighborhood. The best tool you can take with you is a savvy friend with knowledge. If this is your first experience with an old vehicle, be prepared for a sensation akin to driving a giant soap box derby car with a high center of gravity. If you decide to drive the 70 miles, make a few stops along the way and check the vitals. And as TxLaTx said, you're pushing the truck's limit of speed at about 50mph if it is stock so remember to drive 45mph or less just to be safe. In cases like this, I am always guided by what my bladder tells me, as it is more accurate that any instrument on the dashboard.
This advice comes to you from another female bolter who has had her truck for over 40 years.
Have A Safe Journey!
littlebuddie