After a hard drive, my firebird got quiet? Seamless (auto) gear shifting?

Ok, So I've been driving my '86 V6 Firebird Automatic around in the hot Houston weather for a bit. I go to get gas and I'm on my way home, when I hit a nice clean road I like to speed up on. I speed up a little, but there's 1 car there so I don't do much. Then I hit the main road and go up to 50 or so pretty quickly when a light changes at the wrong second and I have to slam the brakes. After that I don't go too fast until I hit the next big road... This is where it starts (Backstory is there incase it's important.)

When I put down the pedal, the car seems oddly quiet and... less torquey. It speeds up seemingly fine, but I can't tell since I usually play my speed by ear as well as what I see. My car is still loud, but not even close to as loud as it usually is on a hard accelaration. On top of that, it seems like it wasn't shifting dramatically like it usually does on the ye'olde automatic tranny. Then when I arrived at my driveway, I tried to get it to rumble out loudly like it does... only the rumble was definitely less loud.

So overall, I noticed

1. Less of a pull (Torque?)

2. Less loud (ALOT less)

3. Gear shifting from the auto tranny is much less dramatic. I couldn't notice it like before.

Sorry it's long, I didn't want to leave anything out. If anyone has any tips and/or ideas, they're much appreciated.

Could one of the cylinders have gone out? (Explaining seemingly less torque/Quieter engine... As well as easier shifting for the trans since it wouldn't be as fast.)

Could it be something that got into the intake/exhaust when I was going fast and braking hard? (Explains the lower torque/quieter engine. If this is messing with the engine somehow, it COULD explain the shifting in the same manner as a blown cylinder.)

NOTICE: I have not driven it since this. It's been about 30 minutes.