Alot of people are moving away from Diablo to HP tuners. If you are just going to use the DS 93 octane tune, without custom tuning then you might gain a bit of HP.
You have a 14, your pcm is unlocked so you have plenty of options you can try. Research them first before just jumping at the first one. You might be surprised on what you select. Regardless of what you do, if you choose to tune your truck, take the time to learn about what you doing, modifying and why.
In addition use the tuning tool as an opportunity to raise your idle RPM to 750 minimum to properly insure oil flow to the camshaft at idle.