i'm not on here much, on pro-touring.com more, but i just noticed your thread. as a die hard firebird guy i must say, please don't put a chevy big block in your firebird. the only acceptable substitute for a pontiac engine would be an ls engine. it's your car but no self respecting pontiac fan wants to see a chevy engine in an old pontiac.
i'm on my 3rd 79 ta, and still have my first car, a 67 firebird. i already have an ls1 and t56 to put in one or the other. the other will get a big inch pontiac with kauffman heads and fuel injection. if you aren't too hip on the pontiac scene yet here are some good websites for performance parts. you can see what kind of power they are getting with stock blocks and stroker kits, or if that's not enough you can get over 500 cubes with the IA II block that butler sells.
www.krepower.com
www.butlerperformance.com
www.tinindianperformance.com
but anyway, i can't wait to see more progress