I had a 73 Ranchero GT that did the same thing two different times.
The first time was an intermittant ignition coil failure.
The second time I had some crap in my float bowls that would block the
ports.
Good luck!
You find the problem, the older cars are so much easier to troubleshoot,
that's why I went with a '72 mach 1.
Dave

"Nevada Larry" > wrote in message
...
> My 66 Mustang quits running after about 5 or 10 minutes. If I am driving
> down the road it restarts and works fine after that. If it happens at a
> stop sign, I have to restart it. It starts immediately and works fine
> after that. If I park it for a while and start it again the same thing
> happens. New wiring harness and ignition switch 4 years ago. Mallory
> electronic distributor and new Pertronix coil. Fuel flow and spark are
> good. 289 4V with C4 automatic. What should I check next? I hate
> intermittent problems. Have lost all faith in this car. Purchased in 1992
> and has been great up to now.
>