Classic/Antique Car Repair: 1967 Mustang Ignition System, painless wiring harness, carburetor problems

Question
Brad,
I have fully restored a 1967 Conv Mustang, 302. 4 B 650 cfm Holly Carb
I installed a new Painless wiring harness and an electronic ignition (blaster). Everything seemed fine for 6 months, then
The engine starts, the car runs great for 15 minutes or so, then the exhaust gets rich and the engine shuts down and will not restart.
These are the things I know:
alternator putting out about 14.5 volts
coil gets very hot (had over 12 volts)
installed two ceramic resisters between ignition key and coil
coil still has 11.2 volts (and still gets hot)
Went back to points and condenser ( still happens)
I have looked for a resistor wire to replace the wire in the painless harness between the key and coil but cannot find one
Do you have any suggestions

thank you

Jack Ehleiter

Answer
It sounds more like a sinking float or drippy needle and seat in the carburetor. To check this run the engine with the air cleaner off until it stalls. With a flash light look down into the bore of the carburetor and see if there is gas dripping out of the main jet. If so, then it is carburetor problems. Check this and get back to me and we will go from there.