Runs 15 minutes then dies and won't start

[davids2toys]

Hi guys, it has been awhile. A couple of more surgeries kept me away for awhile. I have a MSD 6AL box and MSD dist.It has a magnetic pickup in the dist which failed way before this problem. It was replaced and has been fine.This new problem started 3 years ago. Pulled into a cruise night and the car just shut off like it ran out of gas. We all did a bunch of trouble shooting and a cobra friend had a brand new coil. Installed the coil, started up and drove it home. I thought it was the answer, WRONG! The following weekend drove it to a party at a friends house. Ran fine for the 1/2 hour ride and then died in his driveway. installed another new coil but it would not start. We parked it in his garage. I came back the following day to screw with it. i had installed a MSD noise capacitor before this problem started so I unwired it and joined the wires together. Still no start. I called my Roadside assistance and had it flat-bedded back to my house. During some trouble shooting it seemed like the ignition switch was questionable so I changed it out. Started it up a few times and thought all was good. Then I had 2 more surgeries which took me out of commission for about 2 years. So a month ago I got it ready to go for the maiden voyage. It ran great! So 15 minutes into the ride I puled up to a stop sign and it just shuts off. Tried to start it back up, no luck. Had fuel at the carb, so I sat on the side of the road for 45 minutes. I figured it might be the coil and might start after it cooled down. It started right up and I raced home before it died again. I have been testing and inspecting everything and it was passing with flying colors. Cap , rotor, Pick up in dist was very clean and tested fine at 674 ohms. Did the paper clip trick to test the box and it was fine. Check all my grounds, fine. I gave up and thought maybe simulate the shutoff / no start condition and then do the same tests while it was hot and not starting after it shut off. Today I ran it in my driveway. It started and ran just fine. After about 20 minutes it just died. Tried to start it, nothing but spinning. Immediately did all the tests again. everything tested good. Also while cranking it had 6 lbs fuel pressure so that would eliminate vapor lock. I let it sit for about 30 minutes tried to start it, fired right up!!! I'm stumped. You guys have any ideas???