ADJUSTING VALVES / replacing valve cover gaskets on a 12 valve Dodge Cummins / finding the oil leak!

So my Cummins has been leaking a little oil for years, & started getting worse a few months ago. Looking around, I found oil sludge around the valve cover gaskets. They were def due to be replaced.
It's been awhile since the valves have been adjusted too, so while I have them off I might as well adjust the valves, killing 2 birds with 1 stone.
Here's how you do it.
Link to valve cover gaskets- www.amazon.com...
Link to torque wrench- www.amazon.com...
Link to feeler gauges- www.amazon.com...