Runs then dies

For clarification- some info may be redundant.
1. TDC was verified with piston stop to be correct with timing mark.
2: Timing (30’) BTC set at operating temperature
900 RPM, vacuum advance disconnected and
capped. Air cleaner off , choke open.
3. Coil-
6 ohms primary, 14500 ohms secondary (cold)
0 ohms primary, hot
12000 ohms secondary (hot -105-145’)
4. ECU - 84’ and 94’ when it died.
Plugs (NGK) have 275 miles on them.
Spark appears fine on all plugs.
5. Carb rebuilt by major rebuilder 2900 miles ago.
They rebuild for Summit.
Fuel was sprayed into carb to confirm no fuel
starvation. 10” of vacuum was on fuel pump.
Charcoal canister lines are filtered, I added in line filters.
6 . Engine temp when it died was normal (185’) just
above thermostat and choke was open
7. Compression 115# , (+-) 5# between cylinders
At 3600 ft elevation.
8. Car starts and runs fine when cold, problem
occurs only after thorough warmup.
I am leaning toward something in the ignition circuitry although not ruling out fuel issues or other as you guys have mentioned.
The last time out , the car ran as good as ever (maybe best) with settings as described although problem occurred previously and now seems consistent.
Yote