Ok 1st a little history of what the truck has: 1990 GMC C1500 5.7L, MSD HEI Distributor, Hypertech Performance Chip.
Now what I just finished adding is: Shorty Headers, Water Pump, Thermostat, Radiator, all new cooling\heater hoses, O2 sensor, spark plugs and wires, Edelbrock Valve Covers and Air Cleaner.

Truck was running 100% before I installed all the new stuff and now it tries to start but it won't.
You crank on it for a bit and it just blub-blub-blub, dies.

I didn't mess with the distributor besides unplugging the wires, I've confirmed I'm getting fuel and spark.
The tricky part is that the previous owner marked the dist. with a sharpie for the cylinder #'s but it doesn't match the firing order so it can't be right.

I went ahead and wired the dist. to this layout:




My brother is coming by with a timing light so we can check that to confirm and we'll also determine for sure which post on the dist. is #1.

Any ideas regarding this problem please let me know. I was so careful not to mess with anything electrical related but regardless it won't start.