I have a 91 firebird 305tbi. Car came with a new 3' flowmaster catback. Wanting to go hooker shorties. obviously looking for more power but im also hoping for a louder exhaust. Not crazy loud but better then no headers. Let me know! Thanks

 

I used to have hedman 1 5/8 shorties, they were awesome, I got to low 11's with them!
I got a custom made 3" y-pipe with cutouts for it too, they flowed quite a bit and sounded awesome!

 

i have a pair of hedmans on now. They do a good job at a good price. headers don't make the exhaust louder unless the exhaust is dumping straight out of them. when connected to the rest of the exhaust system, the muffler controls the loudness. i have a dynomax muffler and the car sounds the same as when it had the old 305 with factory exhaust manifolds...quiet.

 

Headers won't affect overall sound, but you'll definitely hear the engine idling as the exhaust goes through the headers, a sound I enjoy. Mostly they'll free up horsepower in your motor.

Hooker 2055 or Dyno Don's would be the headers of choice here for shorties with emissions.