2003 GMC van 3500 v8 6.0 L?

[fofoxuxu]

Cylinder 1357 won't work but cylinder 2468 works. what is the problem? thank you.

 

[AUM]

It looks like one of the 2 sides in a V block engine is not producing power.
This might be - No/ improper current supplies,
- No/ wrong fuel supply,
- Compression leak due to wrong valve timing,
- False ignition and/ or injection timing.
There are tons of reasons, better get it checked by a mechanic.