My father is the original owner of our Z, and when I got my license he let me drive it, partly because I loved the car and wanted to drive it for as far back as I could remember, and also because I have moderate mechanic skills to maintain it. It has a rebuilt engine with about 95k on it and I just got some new tires. The performance is a little sluggish though. It doesn't seem to accelerate that quickly, especially when I shift into fourth-it takes a little time to gain speed. I'm just looking for some tips on what kinds of things I should do to improve performance while keeping the car mostly stock and classic. Thanks a lot!