hey, sorry, but this might sound noobish.

but I have a 13b n/a gxl and the engine was rebuilt in 2003. theres is 246,000 km
on it, and the rebuilt engine has about 30,000k on it. now. if I properly maintian that
car which i plan on doing.... how much more mileage can i get out of that car.

i just replaced all the sparkplug and sparkplug wires.

 

That totally depends on whether the engine was maintained before during the 30,000 kms. It also depends on whether a proper break-in was performed, and even depends on what components were replaced during rebuild.

 

A good rebuild should last nearly as long as a new engine.

Just change the oil & don't let it overheat.

Welcome to the forum.
I have a copy of the factory manuals on-line at the link in my sig.