5.3 2014 Silverado Z71 expectations

[MADWHIP]

Hi All,
So I had a 5.3 2014 Silverado Z71 to tune today. It's the first 5.3 I have tuned. No trucks like this were ever sold here in New Zealand. It made 278rwhp with a k&n intake and stock tune. I obviously had no starting point tune file so I just started from scratch. All I seem to be able to make is about 10 extra hp. Is this normal or is my tune junk? I have attached a copy of my tune file (v10) it still needs trans work and the fuel trims done I have also loaded the standard file from the truck. I would hate to think I'm sort changing the client on power but cant seem to make anymore power. If anyone out there has experience with these later 5.3's can have a look and see if I have missed something. These files are nothing like our Holdens. I'm not asking for a tuned file I just want a heads up so I can improve my game.
Cheers

[jc052685]

Might try leaning it out a bit to 1.120 PE. Zero out the AFR Spark Correction table and tune without it.

Not much to be had on those with only a tune. I will tell you they respond well to headers and a cold air.

[MADWHIP]

Thank you JC052685

[MADWHIP]

Ripping my hear out with this truck. I cant seem to get hardly any extra power out of it. I guess I'm at the limit. Just not happy with the end result. vvt and the DI is really kicking my butt. Any help appreciated.
My brain hurts.

[SultanHassanMasTuning]

the newer PCM are not detuned as maybe the holdens were, very big difference. depending on your octane rating, also seems still a bit rich

[MADWHIP]

I'm running .90 lambda but yes I think you are right I'll just have to accept what I have got.