Cm870 timing off??

[Nyluke124]

We recently bought a 07 pete with a cm870 rated at 475hp... took it to local shop to change some cruise control settings and their insite said it was changed to 550hp. We recently had to do the front cover due to oil leak and when putting everything back together i used the wedges that were recommended on the valve cover. After the front cover truck now only builds 32lbs of boost before it was 38. Wondering if the timing was set other than what is on the valve cover when it was switched to 550hp and that is what is causing lower boost??? Also found the egr valve unplugged so i plugged it back in and started getting high egt’s so i unplugged it again.. no check engine light either. Any help would be appreciated thanks!