C18 Head on a C15 Acert

I bought a 2007 379 with a C15 Acert. Looked to have a new head on it. Turns out its got a C-18 head on it which probably is why it runs like a dog on the top end. I'm guessing the head probably just has stiffer springs. I wondering if it needs to have a C18 cam or if a C15 cam will work. Also will the injectors work with that as well. I'm guessing it just needs some tuning to be getting enough fuel to run good. The injectors are 2490709. Any help would be appreciated, Thanks

 

so the internals are the same aswell?

 

I says C-18 right on it

 

So when i bought the truck the ecm as bad so i had cat get me a new one and turn it up to 550 from 475. But the think climbs a hill like its got 250hp so I thought maybe because it has a C18 head maybe the springs are a bit stiffer and if it has a 15 cam maybe its having issues there. And then the 550hp tune they uploaded to the ecm is not working how it should.

 

bottom side of the head next to the air compressor