99 Chevy k1500 5.7 no start after below zero Temp

Ok I've always been the go to guy when crap
breaks and I've always found the issue. Well today
was where that ol saying came true. There's a first
time for everything. So here goes. I bought this
truck 4 years ago. Keep in mind it's got 750k miles
on er with no rebuilds on the engine. Trans was
replaced about 40k miles ago with the upgraded
shift kit and Corvette servos. Had the heads
completely redone shortly after buying it. Replaced
the intake plenum gaskets and also replaced the
spider injectors. Drove for 2 years then ended up
replacing fuel lines, fuel pump, fuel pressure
regulator, fuel filter, spark plugs and wires. Drove
for about a year. Got a steal on a transmission so
put that in last year. Drove for about 5,000 miles
and truck did the typical spit and sputtering for bad
plugs. Figured that much after checking out how
the shift kit worked(barks the tires in 1-2 & 2-3
shift) so any way cost to play right. Well changed
the plugs again and wires cause hey their
warrantied. Been driving just fine up until about a
month ago. The engine would jolt or jerk at about
45-50mph and acceleration is hesitant and idle
dropped to 500rpms (was idling at 700 or so) take
offs became sluggish and would sputter at first but
if I nailed it it would up and go again but was still
hesitant. For the last two weeks it's still doing that
and then started to start hard as though the
battery was weak and it would do the whomp
whomp whomp vroom thing and start but I had
doubts Everytime with how it turned over so slow
at first. Also my mpg went from about 16-18 to 10-
11mpg.  Check engine light is off and code reader
isn't picking up any codes(thought maybe the light
burnt out cause it has never been on the whole
time I've owned it lol) well parked it last night.
Temps got Down to about -20°F and my truck
would not start at all today. I have fuel pressure, I
have spark. Well the engine kicked back, if I crank it
it to long it backfires. Was turning over great at first
but no start, acted like no fuel or no spark so I
checked both, also checked compression and
everything seems to be fine but it just will not start.
Figured ok these damn trucks are temperamental
with the voltage because gm does not know how
to wire things. So checked all the voltage at fuses,
relays, switches and a few sensors. Pulled the
distributor cap as I read on here in a post the caps
go bad really fast well mine all still looked new and
no abnormal signs and I've got beautiful spark. So
whatever happened either happened because of
the cold temps or on first start up. I checked
everything I can think of. Thought well maybe
timing is off. Set the engine to tdc on cylinder 1
and the distributor was all ligned up where it needs
to be.  I did find on the starter housing a long crack
where the armature is.(heard a loud metal banging
in the area) assuming that the kick back did the
damage there.but a kick back indicates a timing
issue I believe. But my timing isn't off. Crankshaft
position sensor would be next guess but there's no
codes? So going in blindly. Any input or knowledge
on this would be great. Can anyone test the crank
sensor like AutoZone or whatnot? Ive gotta get a
new starter  now but I gotta get this figured out.