pressed in..
They are pressed in.
No you can get screw in studs mainly for high performance engines.
They aren't threaded, they're pressed on. You'll have to rent/buy/borrow the special tool to get it on/off or you can damage the pump.
It is threaded into the exhaust manifold.
There is no adjustment- the engine has hydraulic valve lifters.
17 ft.lbs.
Probably a sludge problem.
The 2000 Chevy Impala 3.4 liter engine rocker arm bolt torque specification is 45 pounds. The rocker arm bolts should be torqued in 15 pound intervals.
rocker arms can be tightened right down as their is a shoulder on the stud.
There probably "pressed in" so take a couple of old nuts or balls from the rocker arm, put the nuts on the shaft, then put the rocker nut on and just tighten it up, it willl pull the shaft out of the head. Good Luck
22 ft. lbs.
pull a valve cover and look for roller rocker arms.