The correct procedure on a 95 Chevy Lumina van sparkplug change out
Pull the old ones and put the new ones in. Tighten it until you feel the little crush ring on the plug crush. It will go finger tight then about an eighth to a quarter turn will be stiff then it will get quite stiff. Stop at the quite stiff.
THE ANSWER IS ON A CHEVY LUMINA VAN HOW TO CHANGE SPARK PLUGS. LOOSE ENGINE MOUNT AND USE A TIE DOWN STRAP,AND PULL THE MOTOR FORWARD,ALSO TAKE TO AIR FILTER COVER OFF, VERY HARD JOB.. USE A HOSE CUT TO START THE SPARK PLUGS. $100 JOB.