One thing that I've always had trouble with is seating the plug wire boots onto the plug. If they don't 'click' into place, they will fall off. I just had this happen again when I did my friends SC. I would also move the A/C compressor out of the way. I use bungie cords hooked to the front spring looped over the fender to hold the compressor up. Also, remove the air inlet rubber tube and air filter box top and get it out of the way. I even disconnect the fuel lines from the fuel rail and get them out of the way. It's easier to remove things that are in the way than to try to work around them. If yours has the digital heater/AC control in the dash there will be a sensor for it just above #2 cylinder plug in the heater hose line. Careful around it or it'll rip a gash in your arm. Otherwise, you can get to the passenger side plugs better from the top. I also do the drivers side plugs from underneath. It's a 2+ hour job for the uninitiated. Once you've done it a few times it's not so bad. Oh yeh, use a rachet with a swivel head and a very short extension.
90 5spd, best E.T. 12.250
best 1/4mi speed 112.89 mph
best dyno 388.42 rwhp 419.68 rwt
2004 Cadillac CTS, 14.616 @ 91.84mph.