DT 466E

Hi,
I have a question about my 2002 DT466e.
I recently done an inframe on my engine. I’ve put about 3000 miles on it since then. The issue I’m having is it is burning a good bit of oil, about a gallon every 300-400 miles. The truck has plenty of power and minimum blow by. You can see blue smoke if the truck has sit idling for a little while and after the truck has warmed up you can start to smell the oil burning in the exhaust. I would just like to pick everyone’s brain on the hat could possibly wrong.
I did take the head to a reputable machine shop and checked and repaired valves valve guides etc. They replaced injector cups also.
I replaced the air compressor due to it it leaking oil. Other than that I don’t know. Any help or ideas?
Thanks in advance.