use the GM single piston setup, like the '69 and up had. they fit with any disc brake wheel you can put on your car. there are some 14" wheels which are drum only.

an advantage to a GM kit is you can get most parts at any parts house, and ask for parts for a '69 firebird.

i personally prefer power brakes to manual.


here is a website which might help: http://ourworld.compuserve.com/homepages/David_Pozzi/brakes.htm#Converting_Drums_to_Discs