New Valve & Head Job - Valve Train Noise?

Just had the heads machined and new valves installed (by a reputable "Toyota Only" mech).

Truck runs like a scalded dog now, but I can hear the valve train at Idle (and low speed when cold). Sounds like a little diesel engine. I've heard some people say this is normal, some call it the "Toyota Tick".......the noise never existed before.

Is there any truth to this and can it be stopped by switching to a full synthetic oil?

Also: Gas mileage seems to be a little worse now too.

 

If they didn"t clatter before the valve job I'de say they are loose and out of spec's I would want them adjusted and see where my fuel mileage goes from there.

 

Full synthetic FTW.