I know you can do it with the l36-67, but how about with my engine?
and if so how hard would it be? would I use the lQ4, or the northstar one?

The problem is going to be changing the tune for the larger air flow.

Not sure how it is for the 1990 3800 (if that'* what he has), but on my 95, the upper intake manifold entrance is the same size as the throttle body, so getting a large throttle body would accomplish absolutely nothing.

I swear, theres nothing I can do to this car to make more power out of it, short of a cam or something.

Mild nitrous. But @ 20 years old, the engine is going to wear fast. Of course @ 20 y o anything appreciable is going to have the same effect.

L67 swap...

I could do that, would I have to tune it if I did like a 50 shot or something?

No, a wet 50 shot would be fine with copper plugs without altering tuning. Timing would have to be retarded after 75. You wouldn't want to spray against your MAF, thats the only issue for a smaller shot.

how hard do you think it would be to go about doing this on my car, instaling wise?

On a scale of 1-5. It'* an easy 2. You need to drill holes through the trunk floor to bolt the bottle bracket in. Drill and tap a hole for the nozzle in a CAI pipe. And do the wiring. Most kits come with a fuel line connection that snaps into the Schrader valve on your fuel rail. And the right tap for the nozzle. Zex is King with all the extra'* for the install and braided SS lines with easy connectors.