No Start! Good Fuel, Good Spark

['97 Tahoe]

I am a forklift mechanic, accustomed to on board diagnostics being
built into the trucks. Also new to these groups. Have been searching
them.
Prior to this condition a service engine light illuminated in the
middle of a 2 hour freeway trip, I rompped on it up a hill. no
drivability problems.
Light cleared after restart on return trip.
Then a couple weeks later tough starting, Once it did start, Rough
idle.
Then would run, And start fine. Then repeat the symptoms a couple
weeks later.
Now cranks fine, Long cranks >15 seconds cranking will hesitate like
wrong timing, Or piston coming up on High compression.
Fuel- 62psi and holds. Spark- checked with induction timing light.
Changed the Cap, Rotor, Sparkplugs. #1 plug hole will blow my finger
off when cranked.
I do Not have a Tech 1 Scan tool, But have pulled the codes with a
lesser tool.
I have a P1406 EGR Valve Pintle Position Circuit Fault.
And a P0306 Cyl. 6 Misfire detected.
2 days have been spent checking sensors Ohms and volts and fuses, None
bad.
I have access to Mitchell 1 On-line and have followed the basic
testing as much as I can without the better Scan tool.
Could the cam sensor module in distributer be bad?
My first thought was stretched timing chain, Yet to rule on this.
137K on vehicle.
(My '90 Surburban's timing chain went at this mileage.)
Last winter I completly went through the fuel system, Replacing pump,
regulator, oil pressure switch, relay, connector and terminals at pump
head.

Any thoughts on this?
don

[GiGsolydCustoms]

i had almost the same problem. changing the fuel filter might help you, as it did me.