Plug #1 is the one at the front of the engine. BTW, make sure there is nothing sitting around the coil pack to fall into the hole.
And, I believe, the stock plug is iridium; that's what I use in all my vehicles, vintage and new.
Deep, steel/sand, loaded except standard radio and no smoker's; #08974
Mods: Kappasphere CAI, Clear Image Shorty Header, second horn, visor decals, mudflaps, tonneau cover, brake light flasher, trailer hitch, 'lil Chromies, trunk monkey, retune, DDMWorks backbone, GMPP Suspension, wood grain dash, Solo Quiet cat-back exhaust, deleted:Solo high-flow cat