I think one thing that some forget about things like Seafoam or any fuel injector cleaners or things like that is if you use it regularly or your injectors and everything are clean in general, you probably wont see any difference at all. Now if you've got 50k on the engine and never used any additive or anything, chances are you will see some kind of change, whether it be for the good or the bad.

I didn't use seafoam because I can't find it around here but I bought a bottle of Redline today and poured it into my brake booster as the tutorial describes on these forums. Let me tell you, my truck was smoking for at least 10 minutes!!!!! I must have had a crap load of carbon buildup in my truck.

I've seen the videos on youtube of people seafoaming their cars, but mine had waaaaaaaay more smoke then any of those videos, I'm guessing now my spark plugs are gonna be garbage soon right?

They're garbage now! On a side note, I'd only use Seafoam like that - other injector cleaners can have different chemistry.

you may be right, my truck still blows out a cloud of smoke at startup even today, 24 hours later:) I hope i didn't ruin anything in my truck. I just need to figure out how to change the spark plugs now because i can feel my truck is weak when i start it.