Problem:

Changing cylinder number three spark plug in 4.3 liter equipped S series Chevrolet Blazer or GMC Jimmy.

Steering shaft obstruction can make this plug difficult to remove or install.  A swivel socket may allow access but the extreme angle could cause the plug to crack or break during installation.  

Solution:  

Disconnect the steering shaft from the gear box and move steering shaft aside to gain better access to cylinder number three.  While this seems like an obvious solution, many techs overlook this.  Instead, more time is wasted and more plugs are cracked in an attempt to work around the steering shaft.

Always reconnect the steering shaft before rotating the steering wheel.  If not, you could damage the air bag clock spring.  For reference, it helps to straighten the the wheels before removing the steering shaft.  Be sure to lock the steering wheel so it cannot be turned while the steering shaft is disconnected.

Tip:  In addition to the socket and extension needed to remove the pinch bolt, some penetrating oil and a pry bar are helpful for use when disconnecting and reconnecting the steering shaft to the splined shaft on the gear box.