Relatively Easy (but may still require fabrication/modifications):
* Other GM V6s from the same era: Engines like the Buick 3.8L V6 (various generations, some requiring more modification than others), and possibly some versions of the 3.1L V6 are candidates. These share similar mounting points and bolt patterns, making swaps somewhat easier, but you will likely need to adapt things like the transmission, wiring harness, and possibly the exhaust and cooling systems.
More Difficult (significant fabrication and custom work required):
* Other GM V8s: Larger GM V8s (like small-block Chevys) would be a *substantial* undertaking. You would almost certainly need custom engine mounts, exhaust, possibly a different transmission and driveshaft, plus extensive modifications to the engine bay and potentially the chassis.
* Non-GM engines: Swapping in a Ford engine, or any engine from a different manufacturer, would be a very extensive project involving significant custom fabrication and potentially needing to source many custom parts.
Things to consider:
* Transmission: The transmission must be compatible with the engine you choose. You might need to swap the transmission as well.
* Wiring harness: The wiring harness needs to be adapted or replaced to match the new engine.
* Computer/ECU: The engine's computer system needs to be compatible and properly programmed.
* Exhaust system: A new exhaust system will likely be needed.
* Cooling system: The cooling system might require alterations.
* Engine mounts: Custom engine mounts may be necessary.
In short: While other GM V6s from the same era offer the best chance of a relatively straightforward swap (still requiring significant work), any other engine swap will be a very involved project requiring considerable mechanical expertise and fabrication skills. Researching specific engine swaps for your year of Grand Am in forums dedicated to car modifications would be beneficial.
