How to clean gunk out of new build

A better description of the gunk, gritty,grey slime greasy
Black mud or tar like.
Some idea.
Sea foam engine flush.
I wonder if there is a filter available that is full flow. No bypass. I had a chevy small block that was chock full of grey sludge. Couldnt pour oil into it.
Radiator specialties engine flush, 1200 rpm for 30 minutes and dump and fill with 5w30.
I ran a heavy truck 2 quart size filter with no bypass and changed oil a week later.
Best running 350 i ever owned.