HI ,
I have a 2000 GMC Jimmy with the 4.3 engine , and I've had a lot of success using different lengths of fuel injection hose with a slit cut about 1/2" where the plug tip slides in to hand thread them in , works like a dream & no chance of cross-threading , also I use a sparkplug socket that has a hex on the end & a open end wrench to tighten the no. 3 plug , hopefully this helps sometime !

 

Good advice, but hopefully OP got his plugs changed sometime in the last five or so years