[brucepick]

My '97 Civic HX does about 2300-2400 rpm at 60 mph. I wouldn't be surprised if one of those trannies would work out nicely in your Del Sol. If I seriously need more power I downshift. Duh.

I'm only a semi-mechanic at best, but from where I sit I recommend a tranny swap over a gear swap. You may be willing to spend the time but my guess is, when you get the tranny opened up and see what you need to do inside - and when you start learning about special purpose tools you may need to get the gears off their shafts and back on, and how to set up all kinds of adjustable tolerances - you'll wish you were swapping the whole tranny instead.

Definitely take care of the O2 sensor and any other needs first. In performance modding circles they call it "Stage 0". All the improvements come after you get the basics straightened out. I sure hope you've aired up your tires by now.