2007 Ram 2500 oil burn??
 

I had the engine rebuilt about 10,000 miles ago. It is blowing grey smoke and using a lot of oil. I held a rag over the exhaust and I got oil specks all over the rag, any ideas what could cause this??

You will need to pull injectors, put bore scope in each cyl, check
to see if you have a broken ring. If their ok, could be main bearings.
I know you said new rebuild, but it happens.

Rings or valve seals pick one! Stock cam?