carbon in upper intake manifold

I just replaced my fuel pressure regulator in my 97 5.7 2500 and half of the upper intake was covered in carbon. Is this normal?

Maybe a thin film, but not caked up by any means. That might indicate a lot of blowby or an EGR that might need to be cleaned. Can't say for sure.

Some places it was caked up to about 3/8 of an inch.

Truck also hesitates for a second when you punch it.