I have a 1975 ford 2.3L engine out of a pinto and am having run-on issues.  When i turn the key off, it continues to run for about a second or two.  Its not really a huge problem but definently an annoyance and im not sure if any harm is being done to the engine.  From what ive read, at least with diesel engines, crud can build up in the engine and become hot enough to actually ignite the fuel even when everything is turned off.  Anyone else ever experienced what im dealing with??  The engine is usually running at about 195 when i turn it off.

Also, my engine is only running "good" when the timing is as far advanced as the distributer will allow (way out of spec).  If i adjust it to spec (i think around 6 degrees advanced) it runs like crap.  Any thoughts??

Having it advanced that far will give you that problem when shutting off, you need to up octane. Do you notice under a load go full throttle are piston's rattling as in ping or knock. What is happening is fuel is exploding not burning due to low octane or and to much advance on timming. Throw some AV-gas in there that will give you 115 performance that should clear it up.  Fred

How fast is your engine idling?  Try slowing it down a bit to see if that helps.
mike

100% agree. And check you idle mixture setting to make sure it's not too lean.

Mine was doing the same thing a couple of weeks ago and I put a bottle of Lucas fuel injector cleaner in the gas tank. Now it has stopped so I am guessing the carb was gummed up pretty good. Of course the gas that was in it had been there since March  It could have also been the Staybil that was in there
Just to be safe, I am going to run a bottle of Lucas at every fill up or close to it.

Try retro-fitting an idle stop solenoid on your carb. They are cheap & should fix the problem. When you turn the key on it will power up & set your idle where it needs to be. When you turn the key off it will close the butterflies of the carb & stop the run on. This is what they were invented for.....

If the timing belt is in need of replacement it will do that and is, in my opinion, your most likely problem. Your car only runs with the distributor advanced to the max because the belt is probably screwed. Running super will only cover it up. Dieseling isn't normal on a properly running/maintained engine and ignoring it will end in the engine not running any more because the belt will jump teeth on the sprockets, the belt will shread, the belt will come off completely, or it can cause possible cylinder detonation from being so off-timed which can cause major internal engine damage.

Pinto 5.0 may also be right if I'm not, though it doesn't explain your timing issue. The idle stop solenoid is easily checked to see if it is working and your carburetor should have it on it. It's got a wire going to it and is located near where the throttle cable/lever is. Pop the hood, locate the solenoid, note where the plunger that engages when power is supplied to it is, turn the ignition to on and see if the plunger moved. If it didn't you need a new solenoid.
The plunger on the solenoid should move freely in and out by hand when the ignition is off and it should be pushed out when the ignition is on.