Slant 6 dies when driving

Any engine needs 4 things to run..
Spark
Fuel
Compression
Be in time
If it quits running one of them is missing.
I always check fuel first. Does it have accelerator pump shot?
If it does I check to see if it has spark.
If it does I check to see that its still in time.
Compression, You can usually hear when it's cranking whether it has compression or not.