* Engine Mounts: The engine mounts are different. You'll need to either fabricate custom mounts or source mounts from a Grand Am that came with the 3400.
* Transmission: The transmission compatibility depends on the specific transmission in both the donor and recipient cars. You might need to swap the transmission as well, which adds significant complexity.
* Wiring Harness: The wiring harnesses are different. You'll likely need to either modify the existing harness or source a harness from a Grand Am with the 3400. This is often a significant hurdle, requiring expertise in automotive electrical systems.
* Computer (PCM): The engine control module (PCM) will be different. You'll need the PCM from a 3400-equipped Grand Am. Simply swapping the PCM might not be sufficient; you may need to reprogram it or deal with compatibility issues.
* Exhaust System: The exhaust manifolds and possibly the rest of the exhaust system may not be compatible.
* Cooling System: Differences in the engine block may require adjustments to the cooling system hoses and possibly the radiator.
* Accessories: The placement of accessories (alternator, power steering pump, etc.) might differ, requiring adjustments to brackets or belts.
In short, this isn't a weekend project. It requires significant mechanical and electrical knowledge, along with access to the necessary parts (which might be difficult to source for an older car). Unless you have considerable experience with engine swaps, it's highly recommended you seek the assistance of a professional mechanic. The cost of the parts, labor, and potential unforeseen complications could easily exceed the value of the car.
