they are at the end of the wires that run down either side of your engine. there will be 4 on each side evenly spaced.
but honestly. if you can't find the spark plugs on a V-8, you should probably leave the hood closed.Answer
Their actually under the valve covers. I would suggest taking it in to replace about a $400 job. The platinum plugs are spendy themselves.Answer
Look to the first answer here...if you don't know where they are, you probably shouldn't be messing with them...
that being said...they're NOT under the valve covers and are accessible with a little effort. Soooo here we go!! Pop those funky push pins out of the massive plastic cover on the engine, and take the big boy off. Now isn't that better, you can see the engine!! There's a long thin (about 3 inches wide) plastic cover on each side of the engine on top of the valve covers. Some of the metric 8mm bolts are really hard to get to and really easy to lose, so use care taking if off. It's also very hot in there, so plan on doing this to a cool engine. One of those long covers is extra hard to get out, but you can get it wiggled out if you play around a bit.
Ok set those aside with their bolts. Now you see four round black things protruding from where the covers used to be. Those are the coil overs. The LS doesn't have a distributor, it has eight separate coils that go directly to the spark plugs. Now you have to decide why you wanted to find the spark plugs and which one or ones you want. Here's the cylinder order according to llsoc.com : I don't know what the firing order is, sorry.
Rear of engine (cowl) 4 8 3 7 2 6 1 5 Front of engine (grille)
I recommend unplugging each coil before removing the screw that holds it in (yea there's another 8mm bolt for each coil) and taking out the coil carefully. There's a reputation for leaking valve covers, so if your changing plugs check the plugs and the coil boots for oil. If there's more that and atomized layer on there, you probably have a leak and should get your valve cover gaskets changed. if oils creaping past the gasket into the plug area, there's no way for it to drain out, so your plug and coil end up sitting in a very hot oil bath. Oil in the splug hole fouls out the coils and causes misfires, most often felt as hesitation at low RMPs. AFTER you change the gasket(s)(I recommend changing both), run it for a month (if the misfires aren't to frequent) and double check that the job is done right and leaks are gone before replacing that particular oily coil. They're about 80 bucks apiece!! And there's no reason to replace them all, just the ones that are sitting in oil. You can't clean em, and have them work like new, sorry.
Start the car back up, and see if it runs!!! Hopefully you don't have any parts left over...
Locate the spark plug or plugs. They can be found by following the spark plug wire (a larger black or colored wire leading to the cylinder head). If there is more than one plug, make sure you write down or label each spark plug wire before you take it off. This is important, as on an 8 cylinder engine, you can easily forget which wire goes where.