Does 99 Chevy 4l60e and 2000 interchange?

Yes, the 1999 and 2000 Chevrolet 4L60E transmissions are generally interchangeable, as they both belong to the same family of automatic transmissions used in various GM vehicles during that era. However, it's important to verify compatibility based on specific vehicle applications, as there may be differences in wiring harnesses, valve body configurations, or control modules. Always check the specific part numbers and consult a professional if unsure.