[Tailfin]

The PCV tube runs right across the front valve cover. There might be a beauty cover on top to remove first (mine has always been missing lol). The PCV valve is on the right side (saying all this looking under the hood, not from the driver perspective). The tube comes out of the throttle body on the left side of it, towards the front a bit, and it's larger than the other vacuum tubes on that side.

I would say it's similar to the carb cleaner procedure you performed...except that stuff isn't nearly as robust as GM TEC. Seafoam might be another story. I personally pour the GM TEC right into the throttle body blades, while holding the throttle slightly open as necessary. This makes it easier to pour it in at a controlled rate (or so has been my experience judging from the engine behavior). I also noticed by doing this, it acted as carb cleaner only much better, and from what I can see, it nailed the intake manifold as well. Carb Cleaner is good to hit your EGR tubes with though...and I also pour some GM TEC down in there and let it soak so the EGR passageways get a good cleaning. Just always be conscious of that hydrolock issue.