What transmissions can you put in a 2001 1500 Chevy Z71 5.3L. I have trany out of 2000 or 2002 2500 that was 6L. will it work?

The 2001 Chevy Silverado 1500 Z71 with the 5.3L engine likely came with either a 4L60E (4-speed automatic) or a manual transmission (depending on options). A 6L transmission from a 2000 or 2002 2500HD is a *different* transmission (likely a 6L80E or similar). It will almost certainly NOT be a direct bolt-in replacement.

Here's why:

* Different bellhousing: The 6L80E from the 2500HD has a different bellhousing pattern than the 4L60E used in your 1500. The engine and transmission won't physically mate.

* Torque capacity: The 6L80E is designed for significantly higher torque than the 4L60E. While it *might* handle the 5.3L's output, other components in your 1500's drivetrain (driveshaft, differential, etc.) are not built for the heavier-duty 6L80E. Using it could lead to premature failure of those parts.

* Computer compatibility: The transmission control module (TCM) in your 1500 is not programmed to work with a 6L80E. This would require significant modifications, potentially involving custom programming, which is complex and expensive.

* Wiring harness: The wiring harnesses for the two transmissions are different.

In short, while there might be *some* very advanced and costly ways to make it work, it's simply not practical or recommended to try to put a 6L80E from a 2500HD into your 2001 1500. Sticking with a replacement 4L60E is far more sensible, cost-effective, and reliable.