[Yoda]

1. If going with electric choke, you'll need to find a place to hook it up (don't use the wires feeding your ignition as I believe this has been the source of several problems for me).
2. Some extra vacuum line will be useful as the hookups are in slightly different locations.
3. Get some vacuum 'caps' because the carb spacer has several vacuum connectors which will give you too many connectors once you add the Holley.
4. Get a new gasket for under the spacer - the carb comes with one to go between the spacer and the carb, but not between the spacer & the intake manifold.
5. If you have cruise control, you will find that the connector between the carb & the cruise bellows binds on the carb linkage. I just removed the connector for the time being, but will eventually have to grind off the end of a piece of linkage on the Holley to hook it back up.
6. The fuel line connects differently for the Holley. TBird HQ has a new steel line that is supposed to accommodate the Holley, but I could never get it to fit quite right and ended up putting a crimp in the line. I eventually just cut off my original line so that I could fit an inline filter. I have been cautioned by some that (in general) it is a bad idea to use any rubber line between the fuel pump and the carb of a car because if the pump regulator fails, the rubber can burst, dousing you engine with gas. Many feel this would be a less than desirable outcome.
7. There are two lines that connect from your exhaust manifold to the stock carb. These are not needed for the Holley. You can "wiggle" these out of the manifold. Didn't seem to make any audible manifold leaks so I didn't bother to try to fill the holes in any way.
8. The torque specs for the Holley are in inch-pounds so if you want to torque to specs, you'll need an inch-pound torque wrench.

That's all I can think of right now.