Hey. welcome aboard.
Whats in yer car right now? Motor, trans, rear end?
My regal was a 307 carbed car before I transplated the turbo 6. I learned a lot from lurking around here.
Any car, any motor can be improved on in a few main ways. Get more air in, get more air out, lighten the load, change the operating rpm range, among other things.
To move more air, I would look into an exhaust (hooker dual cat back system is great). I had that system while my car was 307'd and it was great. Also, an open element K&N air cleaner helps a lot too. Swap a 2brl carb for a 4brl. Hi output coil, good plug wires. Swap the cat converter for a straight pipe, if possible, or gut the converter you have. (non emissions test areas only though).
Higher speed? Why? Regals arent exactly made to run flat out. If you mean acceleration (0-60 quarter mile, etc), then that comes with horsepower increases.
Hope that helped you a little. Again, welcome. Enjoy your stay