I have a 73 ford custom. This beast starts and purrss for the first 10 minutes. Then after the 10 minutes it starts acting up. It appears to lose spark or it looses timing. I have replaced the coil, starter relay, starter, gas pump, it has the ignitor points. This truck was running great for as long as i had it. I also checked the wiring to the coil. The 73 has the same wiring as the 72 schematics. I have a red and white going to the temp sensor, a white and red going to the oil pressure. And a Pink wire going to the coil. The pink appears to be a resistance wire. Please help!!!!! My next step is to replace the distributor shaft.