New CM870 long block

[Hemiterry]

I recently had a Reman CM870 long block installed in my 2006 International 5600i tandem dump truck. The turbo is brand new as well and new EGR valve and EGR cooler. The engine is mandated with a stock tune. I’ve put around 700 miles on it and it runs good but I’m noticing grey smoke coming out of the stack even under light load. Is this normal during break in or could I have some sort of tuning or fueling issue? I’m not burning or losing any oil or coolant. Any input would be appreciated. Thanks