What's up, Is it true that to swap from a 350 to a Big-Block in my '79 Z-28, all I need is a new flywheel and new headers?

not quite that simple, but its definitely doable. my bb is hopefully going in this weekend. if you use the search function at the top, and search bb swap, big block swap, etc, you will find some great threads to help you out. good luck.

Here is a list of parts that will work from the SBC...
motor mounts, starter if 168T, fan, distributor, plugs and wires, carb, water neck, alternator, transmission if th350 and my radiator hoses fit right on the BBC.
Here is a list of parts you will probably need...
fuel pump, flywheel, alternator brackets for the BBC, power steering pump and brackets, headers or manifolds for the BBC, 3 row radiator, BBC pulleys, and a few other small items.
This should get you started if not completed.
I used the TH350 that was bolted to my SBC and it has held up so far.... but it is rebuilt.
This is a very easy swap and you will love you're car a lot more afterwards.