Pena dump truck service

Hey guys. I just bought an 05 Mack Granite. I provided the Mack house my vin# and I was told my engine is rated and 370 horse power. I'm sure this has been asked before on here but I wondering if there are any upgrades to get more power out of this old dog without tearing the motor up. My truck has a 10 yard dump body on it and I want to pull a pup trailer. Any advice would be appreciated. If anyone has part #s I'll send you a gift card for some beer. Thanks in advance