An 87 olds 307 cadillac. I think its some kinda 200 trans.

I'm not looking for a big performance boost, I know the easy way to do that is a 350 or 455 swap and a TH400 trans? but thats not my goal, and I don't feel like pulling a good engine/trans.

What are some good inexpensive modifications I can do?
Spark timing?
More fuel?
Headers and true dual exhaust? (Is there even space for this, what options would I have for this?)
Remove the emissions junk?

Does this engine have a carb or TBI? (Fuel mods?)
Does this car have an ECM? Is it tunable?

I'm not looking for much, just a little extra, I know the stock trans has a limit, I don't want to ruin the trans by going past that, however I doubt i will reach that limit.