Please indulge me while I wax philosophically...
It's not a T/A (or a Pontiac for that matter), but when I bought my '86 Chevy truck somebody had cut, chopped, and otherwise pulled/plugged all sorts of vacuum lines. The smog pump was still on the engine, but it had no belt. The truck ran horribly, backfiring all the time, stumbling and rough, absolutely no power. It was so bad the previous owner sold me the truck for a song because he thought it needed a new engine.
I found a factory shop manual (which wasn't easy, because it has the Canadian emmissions equipment for some reason) and put all the vacuum lines back like they belong and replaced the choke pulloff. I put a belt back on the smog pump. I also tightened the bolts on the exhaust manifold (which magically fixed the main bearings the P.O. told me were "spun") and I replaced the oil pressure sensor (which fixed the low oil pressure problem which the P.O. told me had "spun the bearings").
Voila! The truck ran MUCH MUCH better. Pretty good for a 200k mile engine that pulled an RV most of the time. That was three years ago, and it's still going strong. It's still a sluggish 305, but it gets about 15 mpg which is about twice what it got before I started messing with it.
So, the moral of this dribble is: unless you're prepared to completely re-engineer the system, keep it stock. It will probably run better and more efficiently.
On the other hand, it is entirely possible to simply throw it all out the window and start from scratch. You can change out the intake, bolt on headers, recurve the distrubutor, dump the EGR, and stick a Holley/Edelbrock on top and probably make a pretty good running engine that might even make more power. If you're really industrious you can even pull off a cam swap. But it probably won't "start like a stocker" and it probably won't be as efficient as a "stocker."
If you decide to do it a piece at a time you'll find it's kindof an all-or-nothing deal. One change almost always leads to another. If you decide to pull the smog pump, be ready to debug the EGR system because you'll probably have backfires when you take your foot off the gas. After you get the backfires gone you'll probably find it is running rich and fouling the plugs. After you lean it out enough to quit fouling the plugs you'll probably want to recurve the distributor to minimize detonation.
And so forth and so on. It can be seemingly endless.
My advice: Keep it stock. Concentrate on keeping the car looking as good as you have it looking and you'll enjoy it for a long time. Fix things that wear out or break, keep the fluid and filters fresh, and keep it tuned up.
That's my two cents worth. (A REALLY LONG two cents.)
Wayne.
(This posting mechanism really needs a spell checker! :? )