this is my first time so bear with me ; my 85 f-250 / carbed / non-cat / 300-6 /
dies with no warning both at speed and at idle and will not start til cooled down
almost act like its not getting fuel but is new filter and pump and i just rebuilt the carb / it does have a slight exh. leak near or in exh. manifold

 

Sounds like your carb jets need adjusting.

Had a similar problem with my son's 79 Cordoba's 2bbl on a 360 engine. It's early "EMS" Lean Burn System computer was taken off by someone else and replaced with a conventional points/distributer. However, the former owner did not know how to adjust the jets to accomodate the change....so it was hard starting as it kept dying at first. When at a stop, would die at idle or after a long drive. A mechanic friend knew what to do and my son has never had a problem since.

 

If you have the spark module mounted on the distributor, that sometimes gets a heat-related problem where it quits till it cools back down. If it's covered in dirt and old oil, clean it off as that acts like insulation. Put an ice cube or three in a baggie and hold them against the module to see if cooling it quickly restores it to running condition.
-Ed

 

thanks for the replies; to smoky;nothing mounted on dist. has fender icp.
to viking;i dont think its jets -iv let it set in driveway idling for three hours trying to get to do it and it will idle with out missing a beat