Dude for its intended use what you have is fantastic, or save money and buy a roadbike.
Better still if you like tinkering buy a second hand frame "high end one" and build it up from scratch, I have a pinarello roadbike but much prefer riding my hybrid.
As said above if you try to change one thing something else has to change and with a bike that old its not worth it and the cost gets astronomical, much better to build from scratch as I have done and its very satisfying.
If you take your time and look at sites like e-bay you can save alot of money and dont forget research research research and dont end up with stuff you dont need.