Thanks for the detailed post!
If it cranks, all the safeties are OK.
If it starts by spraying the TB. It's a fueling issue.
So, what do you mean by this?
It 'seems' to have 49 psi on a gauge when cranking and under load? Because thats how you test a fuel pump.
https://www.rev-mo.com/product-page/...ressure-tester
Then you will know where to look next, like if you don't have 49 psi... commonly compromised fuel lines (pinholes) internal in the frame/tank, clogged fuel sock, bad pump, etc.
If you did test and do have 49 psi,
You can put a test light on the each injector plug and see if they're getting signal while cranking.
If you're getting signal to the injectors and still no fuel, pull them out. Any half decent repair shop can test injectors from a rig designed for it or with Brakleen and a 9v battery.
If it's not starting with the injectors flowing fluid when activated and you're getting 49psi of fuel out of the rail then by golly call a Priest.