Cool, my mates having a new engine built for his 74 firebird at the moment. bored to 6.8ltr nothing fancy should hopefully push out 400bhp at the wheels. Apparently it did 13 second qtr's when it came out in 74 with 270bhp so it should be pretty good. He's also having some funky gearbox built. apparently its a manual box with an auto shift and a ratchet shifter. Not sure how it all works but apparently its supposed to be good.
Good luck with your build.