Start the engine and let it warm up. Then remove the valve covers and back off each rocker arm nut slowly until a clattering sound is heard. Then slowly tighten the nut 3/4 of a turn.
yes
http://www.centuryperformance.com/valveadjustment.asp
on a 350 engine to adjust valves tighten them down with engine running then back them off until it smooths out probably about a quarter of a turn
No such animal, unless you're referring to the diesel 350. Oldsmobile 350 gas engine production ended in 1980. Sorry, but I know nothing of the diesel 350; perhaps someone else will come along and provide an answer for that motor.
No it is not.
probably need to adjust your valves
With the engine at TOP DEAD CENTER (TDC) Adjust the exhuast valve to .007 and the intake to .005.
In 94 you had the LT1 350 V8.
The oil drain plug on a 1994 Chevy 350 is on the underside of the motor. Look for a bolt in the very center of the bottom of the engine.
no completely different motor
Depending on what motor it is, the most common being the 350, you should want to to start by putting the motor on top dead center, compression stroke. then using the firing order,1-8-4-3-6-5-7-2. Adjust the valves in that order, by turning the crank a quarter of a turn, you will bring each cylinder to tdc individually. Start with number one then move in that order. You want to set the valves at zero lash then give them a third to a half turn further after reaching zero lash.
The 2011 Lexus IS-350 has 24 valves.