What transmission will fit in a 1998 Chevy Z 71 silverado?

The transmission that fits in a 1998 Chevy Silverado Z71 depends entirely on the engine it originally came with. The Z71 is a trim level, not an engine spec. 1998 Silverados had several engine options, each paired with a specific transmission:

* 4.3L V6: Typically used a 4L60E 4-speed automatic.

* 5.7L V8: Usually had a 4L60E 4-speed automatic, though some might have a 4L80E 4-speed automatic (less common but possible, particularly in heavier-duty trucks).

* 7.4L V8: Almost certainly used a 4L80E 4-speed automatic.

To know for sure what transmission will fit *your* 1998 Chevy Silverado Z71, you must check the vehicle's identification number (VIN) or the engine and transmission codes located on the vehicle itself (usually on a plate on the engine or transmission). This will tell you exactly which transmission was originally installed.

Trying to install the wrong transmission will require significant modifications and likely won't work. You should only use a transmission designed for your specific engine and truck model year.