Performance Maximization 2.5L TBI

I've got a 91 S10 with the TBI 2.5L. She's got 165k but runs like a charm. Well..once a run a pipe by the cat (Clogged up, wanna talk about some piss-poor gas mileage...) But anyhow, I want to get as much horsepower as I can out of this motor for as cheap as I can. What can I do?

You've already done it bu eliminating the cat. A free fow muffler might make a tiny difference, and so will a set of headers but might not. I don't thik that it's worth the cost to find out.