Wont Stay Running

[HEAVCHEV3]

Hello there I'm in need of your expertise again ladies and gents.This issue just recently started where truck wont continue to run. Please note that I'm still not driving vehicle daily as of yet because I'm kind of anal would like everything to be up to par before I put vehicle on the rode. When I come home from work I usually start the vehicle and just simply let it idle in the garge for maybe 30-45 mins w no problems at all but just recently I noticed the truck would just die on while idiling and wont restart. The next day all seems fine but it just happened again and I'm puzzled. Everything under the hood is new except rebuilt carb and distrib. Carb (single barrel roch mono) is getting gas. It is a california truck w the EEC system. It doesnt hesitate to start it always fires right up and idles fine but again will just turn off by itself after maybe 15- 20mins. I not familiar w distrib at all so today I unplugged it and took a look I noticed one of the terminals where plug goes to the distrib seems blue greenish please see pics.
Would a bad distrib cause the to happened after it has been started or does it sound like something is wrong else where?

[Grumpy old man]

I doubt your cap is causing your problem ,Sounds more like a fuel issue .Remove the gas cap and run it again if it stalls check your fuel filter.