Sounds even better in the video than the sound clip you sent me. Congratulations! Feels great, doesn't it?! My 427w smoked just like that when I first started it. Of course my problem was operator error (mine) on setting timing and
oil getting sucked into the intake combining for a confusing issue. All sorted now, though!
On a side note, make sure you install a steering wheel before you leave the garage. Just a little safety brief for you.