cool, my first teg was a 1989 LS as well. I tell u that thing was so much fun it became an illness!!.

but by now im sure you've relized that the cost of upgrading your engine is gonna cost you more than the car itself!!>. honestly drive it the way it is (go to home depot and custom fab yourself an intake, even a exhaust), and toss it when u have enough $$ to pick up somthing else (g2 or g3 integra, or even a 92+ civic)
It will be alot easyer to mod those babies because there is tons of aftermarket support for them. plus chences are there will be lots more people out there that can help you along the way.

oh and by the way you can put the ZC browntop engine to your list of possible engine swaps

 

For an '89, he'd need a late model Integra black/browntop engine... it's a half-breed between the brown and the black top engines... basically a browntop engine with a black valve cover and blacktop electronics system.

For what it's worth, you mean 90+ Integra or 88+ Civic. It's almost as easy to work with an 88+ Civic as it is a G2 Integra.