1996 Chevrolet Silverado crank but won't fire

I have a '96 Silverado 5.7l vortex 4x4 that won't crank.

Here is what all has happened and what I have done so far:
1st it backfired through the motor and blew the intake gasket out on the back drivers side. I replaced the gasket and it ran fine for about 6 weeks.
2nd it backfired again through the motor this time I had to replace the top portion of the intake and it ran fine for about 2 weeks.
This last time it had been running OK but would not start, I wiggle around on the wires at the top portion of the motor checking all the sensors and connections. Tried again and it started up fine. Started OK 4 or 5 more times OK. The next morning it started OK and I got not even a mile down the road and it just shut off.
So I checked all the wires again like before with no results, replaced the mapp sensor because the boot looked worn and didn't fit tight, nothing still.
I had run codes earlier and it came back with crank sensor. I replaced that and it still won't crank.
It seems like its not getting fire. It turns over freely but then nothing.
Next step I plan is check the distributor, rotor button and control module.
And yes the rule pump is work.
Any other suggestions?

Thanks!