Captainofiron, if you are new to town, these are some other shops/car events you might like to know about, although they are not all muscle-car oriented. (Sorry if you know all this stuff already...) There is a lot of traditional hot rod and custom activity here in Austin, in part driven by a TV show that features:
http://www.austinspeedshop.com
and the car club that runs the Lone Star Roundup:
http://lonestarroundup.com
which is:
http://www.kontinentals.com
This is another place that puts out incredible stuff:
http://www.mercurycharlie.com/index2.php#/home/
Then there is Cars and Coffee, which caters to everything automotive, from exotics to rat rods and everything in between:
http://austin.carsandcoffee.info
and Motor Austin which lists a variety of events:
http://www.motoraustin.com
Welcome to Austin!
psw