still missing

[ShewFamily@aol.com]

Walt,
Try a coil, distributor cap and rotor button.  Sounds like something electrical 
that is causing a problem when it is getting hot.

A coil can sometimes act that way.  You can buy one at Advance Auto or Autozone 
for about $10.  I have also heard of a situation where a crack occurred in the 
distributor cap and as the car heated up, the crack widened enough to cause the 
spark to arc out to the block.  Same can happen with a cracked rotor button.  
Good luck.
John Shewmake
'74 TR6
Chattanooga, TN