Yeah just the headers and engine mounts to do that will set you back a grand. Schumacher makes the parts to go /6 to 440 and the tri-Y headers to go with, but yeah, the coated headers are $800.
I started my build with a /6 car too. I've done some bodywork, but mostly all my money is in the drivetrain and suspension. And even before the T56 I'm more than $10k into it, and I went small block. Granted I probably spent more on suspension stuff than they did, or you have to, but it really adds up quick.