Priorities are the way I'd go, starting with the three big safety items:
1. Brakes. Without brakes, you die. Old cars usually have ancient brake fluid and leaking wheel cylinders. If you're a mechanic, start with a thorough inspection of the brakes. Replace worn out wheel cylinders, shoes, and have the drums resurfaced or replaced if worn out. Flush ALL the old fluid out, and replace with new. If the brakes are still spongey after you're sure you have all the air out, you probably have a bad master cylinder - replace that too. If they're power brakes, be sure the booster is good. Good time to check out the wheel bearings and wheels and tires, too.
2. Steering and suspension. Losing control of a moving automobile because something in the suspension or steering breaks is no fun. Inspect the steering components, ball joints, power steering pump, hoses, etc. If they're original, they're suspect - replace all the old bushings and worn parts. If they're in good shape, lube them up good. Check the shocks next, then the springs. Leaf springs wear out just like coil springs do, and are rarely replaced or repaired.
3. Lights. Headlights, taillights and brakelights are essential.
Next come the dependability items:
4. Motor. If the car runs, so much the better - it can usually be made to run more reliably. At this point you need to make some plans of where you're going with the car. Does the car have to be "all original", or can modern upgrades enter the picture? Its likely that the distributor (if original) is inaccurate and worn out - replacing it with a modern electronic unit will result in better performance, hotter spark, and so on - as will the coil, plug cables, plugs, etc. If the carb. is in good shape, and you can set up a good time for the motor and it holds, you can move on to other things. IF the motor just won't idle or run quite right, much more troubleshooting may be needed.
5. Accessories. Here's where you check out all the items that help the car operate and the motor run. Water pump, starter, starter solenoid (seperate item on these Fords), fuel pump, radiator, alternator, battery, etc. Look for leaks and signs of lots of wear. Pulleys that squeal or wobble are signs of trouble, as is a noisy pump or corroded wiring.
6. Transmission. If its an auto, service it or have it serviced, getting new fluid in there and the gunk cleaned out. Have the tech give the
tranny an inspection. If its a manual and it all works fine, you're good. If its NOT all fine, time to fix that too. Sure, its POSSBILE to get back and forth to work with nothing but 2nd and 3rd gears, but not a lot of fun.
7. Drive train. CHeck out the diff and gears. If all is tight and quiet, hurrah, you've ahead of the game. If you have mysterious noises, they may well be from the driveshaft, u-joints or gears. And such noises are often expensive noises.
There are lots of other things that COULD go wrong, of course, but these are the major highlights.
In my experience, these old Fords are pretty tough, and will keep going despite some pretty extreme wear.
But you should think defensively. When you drive down the road to WalMart you will probably not have to make a panic stop.
But if you DO, it makes a lot of difference if those brakes are up to the task. I'm serious about the priorities. Shoot, we can always walk home from a broken down car.
Its hard to walk home with legs broken in an accident caused because the brakes failed!
Best of luck - take some pics and make it a project, post 'em on here and let everybody kibbitz. It can be fun!
How to get a '66 to drivable condition 
