So I'm thinking about building a turbo or supercharged small block for my Dart. The only thing set in stone is that I'll be using my W-2 heads. Does it make sense to use a 340 or 360 or should I build a stroker for it? I have a bunch of other questions as well, but those can wait until I get some more info.

How are your welding skills? if they aren't good, go w/ a supercharger. As for engine parts, if you ask/tell the seller what the application is going to be they should set you up with the right parts. It all depends on your budget and performance goals. For something that will be 6-8psi you don't need a lot of special parts. If you are going to push 12-14-16 you'll need to ask about special pistons, coatings and so on.

Here's some basic questions:

how much power?
Street driven? how much?
how many days at the track?
race or pump gas? alchohol?
$$$ to spend?
fabrication skills?

Like said, turbo installations require a ton of fab work, but ultimately are a more efficient design.

Supercharger setups are almost turn key, kits are everywhere for SBM.

The rest of my answers are based on the questions above....

I have done both. If you have average welding skills, I would go with turbo. The hardest part are headers and that is easy by just using a set of shorties!

As for cubic inches, like mentioned before, need to know your goals.

I'm looking for street/strip with more emphasis on street. I'd like to be able to drive it to the track when I want to though. I want around 600 to 650 horsepower but I don't want it to be a pain to drive. Pump gas is a must.

"I'm looking for street/strip with more emphasis on street. I'd like to be able to drive it to the track when I want to though. I want around 600 to 650 horsepower but I don't want it to be a pain to drive. Pump gas is a must. "

Exactly the reason I went turbo with a FAST system. In addition, I wanted to retain PS, PB, AC, etc.

Turbo.
Go with a mild engine build. Use a turbo specific cam and a basic block setup. Spend a little money on the heads but put most of it to EFI.