couple tips when it comes to spark plug changes
so I did my spark plugs today. havnt don't it on this motor before(used to own a Tahoe 5.7L V8) wanna spread a couple things I ran into today while doing it. first if you have a cold air intake replacing the old intake all the way to the throttle body your day will go by faster.
first of all I started out with loosening up the bolts holding down the coils. they are 10mm nuts. the coolant lines crossing over the intake manifold get in the way of the second driver side and the 1st passenger side coils. they are held in place by two clips, one on each side of the intake manifold. undo the clip and the lines come loose, I also removed the clip's mount so I had more space, again 10mm bolt. the coils simply need to be pulled straight up to release, I rotated them slightly while pulling to loosen them and not risk breaking things. once you remove the coils the fun part starts, on mine I got lucky none of the plugs were rusted in (like my old chevy used to be notorious for) i went out and bought an articulating joint for the socket. it comes in handy for the rear plugs due to them being way back there. as for putting the new plugs in (make sure they are gapped properly first)
I used an anti seize compound from autozone on the threads
to avoid crossthreading the plugs put them in by hand first couple turns, then tighten them down with the ratchet.
after hitting the spot where the crush ring contacts I went one quarter turn past that point to make a good seal (im sure there is a proper torque spec but I don't have a torque wrench)
drop the coil back in push down firmly lining it up in the mounting lug, tighten down the nut and put the wires back in and button everything back down and that is all.
btw took the dak out for a ride on open road did a couple 0-60s and it is now running about a quarter second faster.
oh as for the old plugs. they looked pretty old and eaten up, no fouling but the gaps were horrable
.050, .055, .050, .045, .060, .045, .055, .065" the proper gap is .040" for the autolite 2932 on the 4.7 V8 (not HO)
sorry for lack of pictures phone was dead