Will a 1996 transmission fit 1999 suburban?

It's unlikely a 1996 transmission will be a direct bolt-in fit for a 1999 Suburban without significant modification, if at all. While they might be the same *basic* type of transmission (e.g., both 4L60E), there were likely internal changes, valve body differences, computer interface differences, and potentially even slight case variations between the model years.

To know for sure, you need to:

* Identify the exact transmission: Find the identification code on the transmission itself (often on a tag on the side) and look up the specifications for both the 1996 and 1999 transmissions. You need the *specific* transmission code, not just the general type.

* Compare the specifications: Even with the same basic model, differences in bellhousing bolt patterns, output shaft length, torque converter, and computer control interface can prevent a swap.

* Check for compatibility with the engine and computer: The transmission needs to match the engine and the PCM (Powertrain Control Module) of the 1999 Suburban. A mismatch can lead to poor performance, damage, or even non-functionality.

In short, while it *might* be *possible* with significant work (custom adapter plates, wiring harness modifications, etc.), it's not a straightforward swap. It's much safer and easier to source a transmission specifically for a 1999 Suburban.