Exhaust smoke on acceleration, what could it be?

I'm getting grey smoke on hard excelleration going up through the gears but I don't see any idling or crusing down the road at 65.
I have a detroit 60 series 14L with fresh inframe including new injectors and injector cups.
Not losing any coolant. Using some oil but not more than expected while breaking in new pistons and liners. Use 1 gallon in the 1800 miles.
Also has a slight shutter in the fast idle which did not have before the inframe.
I'm thinking it might be the turbo getting weak but not sure if that is possible. Turbo was not replaced.
Not black smoke but more of a grey and none if reved up.
Also is is a 2000 non egr motor. No egr cooler or valve. One of the first 14 liter engines.
Please give me suggestions where to look.

 

Actually I did the inframe myself.
I locked the gear down before removing and held while cam was out.
Not that I couldn't got it wrong while reinstalling the cam.

If it was off one notch, wouldn't it be consistent smoke.
Smoke seems to go away at above 1500 rpms, I think though that is close to where I shift around 1650 to 1750

 

If it is the turbo seal, any guess how many miles before it lets loose or gives out?
I'd hate to let it come apart and leave peices in the new engine but also 800 miles home and I prefer doing the work myself.

 

Yes, Air filter is very visable on my Volvo 770.
Was changed approx. 10,000 miles ago and still looks good.
But thank you for the reply as manytimes I over look the obvious.
Kinda wish I could run without an air filter as they are the first thing that cuts fuel economy but I would be to afraid.

 

I checked injector o-rings and they looked fine. Also retorqued the hold down bolts.
I did not prelube the turbo before starting it or keep it from running. Probably should have. Which leads me back to the turbo seals.
Also primed it on starting fluid which might've been hard on the turbo seals also. Was quite hard to get primed. Used about a can of starting fluid.