Detroit 14 ltr issue

Can someone help.
I have a 2007 Western Star, 14 Ltr Detroit .The 1st 7 hours every day, power is low, very low the first few klm. After 7 hours or so, power is much much higher, where it should be.
During the 1st 7 or so hours, coolant temperature climbs above 215 degrees, exhaust temperature never goes above 690 or so, regardless of the pull.
After the 1st 7 or so hours, the engine runs much smoother, quieter and power is much higher, coolant temperature no longer climbs and exhaust temps go up to 725 degrees, which I believe even for this engine a low still.
The local Detroit shop replaced the turbo, did a full tune up, but no difference.
The EGR and EGR cooler are 2 years old, so I'm told ( I've had this truck 3 months only)
Every filter has been replaced on the truck, ( every 15,000 klm) zero coolant loss , doesn't burn oil.
38 years in this business, but I'm in need of help with this one, seeing as it's my 1st EGR truck.
My thoughts are its VPOD or EGR related, yet I'm really not sure.
Is it possible the VPOD is telling the EGR to send too much exhaust to the intake?
Any input would be greatly appreciated.
You can also text me at. 905 746 5505
Thanks again.

 

I hear ya, it's in the works, actually that's how the turbo problem was found, by the guy who was about to start the delete.
But yes, the CAC is new, and all was checked, twice, and besides a tiny leak at a clamp via soapy water test, no other leaks were found
I have 42-44 Lbs boost.
Thanks for your support

 

No codes come up, but that's not to say theres an issue with any electronic device.
I'm curious as to what temps others are experiencing with the exhaust with this motor .
Although I've been dealing with a Detroit only shop, ( they are engines only shop, nothing more) I'm not overly enthusiastic about their efforts. They want to put a six pack of injectors in the engine, and in the same breath they say "no guarantee that will solve your problems ".
Sure, just throw $5000 down the drain, I got lots !!!!