im trying to come up with speakers.i have a standard am radio with one dash speaker. i would like to put one speaker in the rear also.will this work.where can i get speakers that are ok to use with the stock radio that are priced reasonable . thanks again,tony

Hard top or convertible? (I don't quite remember?)

Assuming it's a HT, you have a better choice of speakers. And you can mount them under the rear deck with out cutting anything and hidden by the rear package tray cover etc...

Another popular "fix" for many especially vert owners is the 6x9 speaker boxes that you can set on the back seat when driving and using them, and unplug and put in the trunk when your not using them (or on the floor etc) You just have the speaker wires easily acessable to plug them in again.

In a vert... with out getting creative and with out modifying anything... it get's a little more dificult.

eBay is where I've scored on some great car stereo components. Do your home works, know what your looking for and be patient. You'll get some GREAT deals that way!

With out doing much more to your system, I'd suggest just a set of 6x9's. You can add more to compliment them later, but they will be about as good as it gets with just a stock radio... but still look for great quality at a good price rather than just something at a great price. You'll be happier!

Infinity, Kenwood, JBL, Kicker, etc. Higher end.

Brett - 67 Drop Top 455!

If you are going to use your original AM radio, you can't use modern aftermarket speakers. Modern speakers are 4 ohm, while vintage speakers are 10 ohm. You can get reproduction speakers, 8- 10 ohm, here:
http://www.turnswitch.com/speakers.htm
You'll have to run a parrallel line off your dash speaker to the back. The service manual will show where the optional rear speaker was mounted,
http://www.1968firebird.org/illustrated/misc/antrad1.html
however, that speaker was only intended for FM radios.... don't expect your AM radio to drive 2 speakers easily- its very low power.
If you want better quality sound out of your AM, I'd concentrate on reconing or replacing your dash speaker. If you want un upgrade, but still want it vintage, I'd look into an AM/FM stereo from your same year. If you want modern good sound without cutting too much, check out Custom Audiosound. If you want great sound and don't care about originality, there are infinite options, but you'll have to modify the interior.

Nice catch John... I over looked the "AM" in the question... Doh!

Brett!