2010 6.4 mpg issues and power loss
 

I have a 2010 f250 with the 6.4. Mods are dpf delete, egr delete, turbo back exhaust, intake , spartan tune running 275 early lock. I have 37" tires on 22" rims. Gearing has been changed from 355s to 411s. Now here's the problem, gradually I have noticed the mpg getting worse and power seems to be dropping as well. Looking for and advise or ideas here cause I'm stumped