Car stalls out sometimes and has difficulty starting

As when an ignition module cuts off, then after cooling off, works again.
As when a faulty alarm relay cuts the engine out intermittently.
Many new parts in there now, is the distributor pickup coil new too?
Many more parts can be replaced at random without diagnosing. To save time and energy, diagnose. When it is having a tantrum it is time to check, motor needs fuel, spark, and compression to run and by what is happening, one needs to find which is absent, which keeps the motor from running.
Does it have spark, injector signal? A 12V led test light or a noid light is used to detect the quick electric signal.
My opinion is it's electric issue, ignition component failing (pickup coil, control module), alarm, and/or possibly the ignition switch.

How To Test The GM Distributor Mounted Ignition Module

DTC P1374
The 3X reference signal is produced by the ignition control (IC) module. The IC module calculates the 3X reference signal by dividing the crankshaft position (CKP) sensor 7X pulses by 2 when the engine is running and when the CKP synchronizing pulses are being received. The powertrain control module (PCM) uses the 3X reference signal to calculate the engine RPM and the crankshaft position at engine speeds above 1600±150 RPM. The PCM also uses these pulses to initiate injector pulses. The PCM compares the 3X reference pulses to the 24X CKP pulses and the camshaft position (CMP) sensor pulses. If the PCM receives an incorrect number of pulses on the 3X circuit, a DTC P1374 will set and the PCM will use the 24X CKP reference circuit for fuel and ignition control. The engine will continue to start and run using only the 24X CKP and the camshaft position sensor signals.

Diagnostic Aids
• DTC P1374 can be caused by secondary components leaking high voltage into the IC module.
• Inspect for the following conditions:
- Incorrect harness routing near secondary ignition components
- Ignition coil arcing to wiring harness or IC module--Inspect the ignition coils for the following conditions:
• Cracks
• Carbon tracking
• Other signs of damage
- Ignition coil arcing to wiring harness or IC module--Inspect the ignition coils for the following conditions:
- Secondary ignition wires arcing to wiring harness
I would sugest you take your vehicle to a qualified repair shop an have it diagnosed , but i can tell that's not your way , is it . We diagnose not replace part's .
Replace the IC module. Refer to Ignition Control Module Replacement .
Did you complete the replacement?
Go to Step 11
--
10
Replace the PCM. Refer to Powertrain Control Module Replacement .
Did you complete the replacement?
Go to Step 11
If it starts an runs it's not the crank sensor behind the crankshaft pulley .

check that the coil is the correct voltage in use start/ run 12 volts or start 12 volt run 7.5 volts ( a 7.5 volt running on 12 volts= faulty ignition resistance wire == all the time will fail from over heat condition)
next feel the coil when it stops --it should be warm but not hot to the touch
next test/ replace the ignition control module
These items will loose capacity to operate if they get too hot from component failure but in cooling down will again work until they get hot again

replace fuel filter and if it continues have pump pressure checked

I`ve ecountered this problem a few times. It can be nerve racking and enough to drive you mad. The problem lies in the DISTRIBUTOR assembly. The electronic coils and ignition module get weak and break down as load increases. I would have the Distributor looked at. This is a common problem with these bullet-proof cars..

Sounds like the ignition module that sits under the coil packs ... did you ever get any codes out of it when the light was on ?

What I see the most often is a stalled engine with a loss of spark when driving. Once the engine cools off it will sometimes start and run fine for a short while then do the same thing again. Often, but not always, the pickup up coil or ignition module [both are under the distributor cap] have to heat up quite a bit before they will act up. I replace about 10 ignition modules for every one pickup coil but either one can cause the same identical stalling problem. I keep a few known good modules around as test units so I can just replace a suspected bad module and road test it to see if it works. Another thing that can go wrong in these distributors are the magnets built into the pole piece. A weak or cracked magnet can cause all kinds of odd problems such as stalling when placed in reverse, misfires over 1,000 rpm, etc. Worn bushings in the distributor can also cause problems. As far as a specific test you can do to see which part is failing? I wish there was a relaible one. I've tried using a lab scope and module testers to diganose the culprit but you have to catch the problem as it's happening for those tests to be accurate.

first i would check or replace the fuel filter. then check the fuel pressure at the fuel rail, and fuel pressure regulater. how many miles?

Check voltage at coil. Check coil output (spark should be healthy even at 1/4" away from ground). If OK, then change module The only testing on module is with a special tool. Therefore if contacts are clean, that's all you can do with it!