Have an 87 Cherokee Pioneer 4wd 4.0Liter designated as high altitude on the firewall sticker.

Does anyone know the difference between a CPS with high altitude and a standard CPS w/o high altitude?

If your jeep is located in a low altitude region can you run the low altitude CPS even if the jeep was high altitude setup from the factory?

What is the difference in a jeep setup from the factory as high altitude?

 

As I recall, the HA CKP was advanced a couple of degrees from the standard (2-4 or so, probably not much more than that.)

Installing the HA CKP is a fairly common "performance mod" on standard RENIX, with mix results (per reports from the field.)

You can probably throw a standard CKP on the HA RENIX, as I do not believe there's any significant difference in the ECU (the timing curves may be a bit different, but nothing that the system can't adapt to.)