Here's why:
* Engine Family: The 4.3L V6 in those years was generally the same engine family.
* Major Changes: There were likely no significant design changes between those years that would prevent a swap.
* Compatibility: GM usually kept component compatibility within the same model generation, especially for major components like engines.
However, there are a few things to consider:
* Specific Model: There might be minor variations depending on the exact trim levels (e.g., base model, extended cab, etc.)
* Transmission: Make sure the transmission is compatible. Automatic and manual transmissions may have different bolt patterns or other compatibility issues.
* Computer/ECM: The engine control module (ECM) might need to be swapped or reprogrammed for the newer year model.
* Wiring Harness: The wiring harness may need some adjustment or adaptation depending on the specific year and engine configuration.
Recommendation:
To ensure a smooth swap, it's always best to verify compatibility with a reputable parts supplier or mechanic. They can consult resources specific to those years and models to confirm the interchange.
