60 series 12.7

You are able to hook a laptop to it? Verify that after cranking it shows SRS Received as Yes.

Did you run the overhead, and did you turn the engine over when the cam gear was out?

 

So this engine will not fire unless it sees both TRS SRS once its running if it looses one it normally stays running untill you shut it off
Have you checked the Bull gear for play ?

 

Have you primed and pressurized the fuel tanks? Won’t do it simply by cranking.

 

I know next to nothing about a Detroit, but have you checked fuel pressure while cranking?
I know some engines will not fire the injectors until a minimum pressure is seen.

 

This is not the Case on detroits but yes there needs to build a few psi in the head for the injector to deliver fuel even the the ecm opens injector

 

hit it with a shot of starting juice takes awhile sometimes to get the air out of the head!