300zx(N/A) or Integra (GSR)

[CoolGuy02]

do you have to do it for every 60k? what if you don't do it?

[zx92na]

It should be done every 60k. You run the chance of ruining the engine (pistons, cams, etc. start hitting each other) if the timing belt breaks. All cars have these types of services, so it's not anything limited to the Z. In addition, it keeps the car running trouble-free, so it should not be skipped.