Why would an 88 town car with a 5.0 run and then die when it warms up?

You know... I had a problem just like this on an 82 corvette. I trouble-shot it to the throttle position sensor. I cleaned the contacts at the connector and the sensor with a short bristle brush and alcohol and it fixed it. It might not be your problem but it's easy and it's free so it's worth a try.

inj mod or dist pick up

The TFI ignition modual in the distributor is probably bad. It is cool by the distributor so when the engine gets hot the modual over heats. Most parts stores can test it for you but it takes a special socket to remove it. Common Ford problem