Caveat EmptorAlthough the entire TPI system can be swapped over to a non-TPI car, this is not only complicated, but stock TPI systems are notorious for choking off high-end power, so it's not a cure-all for a weak performer.
We highly recommend www.thirdgen.org as a great resource for a lot of accurate information. Like any Web site available to everyone, though, there can be some less-than-correct opinions at times.
Most importantly, before you soldier off to the nearest junkyard in search of these crusty jewels, make sure you're bolting them onto a solid car. Also remember that these parts are not going to be around forever-this is a finite window of opportunity in which they are available in quantity. I bought my first GTOs in the early '80s for a few hundred dollars, and the junkyards were full of them. Now original GTO or Trans Am performance options are like gold. Does history repeat itself? I'm betting on it.