* Similar Platforms: 1991 and 1992 Chevy 4x4 trucks were likely very similar, especially if we're talking about the same body style (e.g., C/K 1500, 2500, etc.). The transmission mounting points and bolt patterns probably remained consistent.
* Transmission Type: The *exact* transmission type is crucial. You need to know the specific model number (e.g., TH700R4, 4L60E) of both transmissions. Even minor variations within a transmission family can cause compatibility issues.
* Transfer Case: The transfer case linkage and possibly even the transfer case itself might need to be considered for compatibility.
* Computer Control: Automatic transmissions in this era were increasingly computer-controlled. There's a chance the PCM (Powertrain Control Module) might need to be programmed or replaced to properly interface with the new transmission. This is less likely if the transmissions are identical, but still a possibility.
In short: While it's *probable* the transmissions are interchangeable, you absolutely must verify the transmission model numbers from both trucks before proceeding. Cross-referencing the numbers with a parts catalog or online resources will help you determine compatibility. If there's even a slight variation, consult a mechanic specializing in these trucks. Attempting the swap without proper verification could lead to significant problems.
