95 blazer cranks but wont turn over

My 95 chevy blazer 4x4 4.3 L vortec V6 died out
on my son while he was turning around a few
nights ago and I checked
and went through everything i could possibly think
of from the fuel pump to the fuel filter to the relays
and fuses i also checked my distributor the coil
spark plugs and wires i primed and used both gas
and starter fluid spray and i still cant figure out why
it wont start. It sounds like its gonna start but it
just wont turn over. I'm beyond stressed and need
some input and direction on what else i should do
or check.