My 83 T/A is my first Firebird, as well as my first small block Chevy. I've got it running and driving nice, but its had one lingering issue; it blows smoke at startup, and most embarrassingly, if I idle at a stoplight, when I pull away at the green, it fogs smoke on the car behind me.
I decided to tackle the valve seals this week. I've never done valve seals, never really done any head work at all, but I watched the videos, read the threads here, and dove in. Breaking the keepers loose and getting them back in while holding the spring down was probably the hardest part, but I took my time and enjoyed the work overall. Even found a bent pushrod, and the local parts store had one in stock. The seals were very crunchy and way overdue. I found about 50 different ways and methods on how to set the valve lash, including every different torque opinion out there, but I followed the service manual.
Took it for a rip today after I finished, and it runs good and zero smoke now. Pretty sweet.
I know valve seals are boring and old hat for you GM guys that have done it 1000 times, but most posts here sometimes feel like just people with problems they want answers to, so here's a little success story from a novice thirdgen guy.

 

Not 3rd gen, but I did the seals on my Toyota 4-valve V6 engine.
And a valve dropped into the cylinder. I didn't take the head off. The EXH valves are stainless steel, so magnets won't work.
I was able to get the valve back in the guide using a coat hanger, HF "borescope" inspection camera, and a shop vac.
It took many tries to get the perfect alignment, but surprisingly it was back in place in about 1 hour.

 

Oof. Dropping a valve was my nightmare. I used the rope trick; I didn't trust my little compressor to hold it up.

 

I used the air adapter. I had an inline regulator set to about 40 psi - just enough to keep the valves closed with the piston at TDC.
BUT the time between the end of one night and the beginning of the next, the regulator was removed to blow something or me off.
So I connected the air line and resumed work. The engine shook for some reason, but I continued. Full air pressure drove the piston to B DC.
And when the valve locks were removed with a special tool that you whack and a magnet catches the locks, the valve disappeared.

 

Ha! I bet that was one of those moments in life that happens in slow motion, watching that valve disappear into the abyss.