My dads 1995 Honda Civic DX is being handed down to me. I'm not very good when it comes to tuning. I want to get the most speed, power and acceleration from the engine and transmission. To help with the cost, I'm not having any performance parts installed. The only parts that will be changed are the gears/ratios.
Changing ratios will most likely require a performance oriented transmission, which would cost quite a bit. You'd be better off with ECU remapping, catback exhaust and cold air intake.
As far as I know you can't do that without swapping the transmission and that would be very expensive.