* Different Bolt Patterns: The 4L80E has a different bolt pattern on the transmission case than the 700R4. This means you'll need an adapter plate to mate the transmission to the engine.
* Different Output Shaft: The output shaft of the 4L80E is different, requiring a new driveshaft or modification of the existing one.
* Torque Converter: The 4L80E uses a different torque converter than the 700R4.
* Computer Control: The 4L80E is electronically controlled, requiring modifications to your vehicle's computer system or the use of a standalone transmission controller. This is a significant undertaking, often involving custom wiring and tuning.
* Physical Size and Weight: The 4L80E is physically larger and heavier than the 700R4. This might require modifications to the transmission tunnel or crossmember. Exhaust system clearance may also be an issue.
* Cooling: The 4L80E generates more heat than the 700R4 and may require a more robust cooling system.
In short, while it's *possible*, it's a complex and involved project that's best left to experienced mechanics or transmission specialists. Simply buying the transmission and dropping it in won't work. You'll need fabrication skills, mechanical knowledge, and possibly access to specialized tools and tuning equipment. The cost of the parts and labor will significantly exceed a 700R4 rebuild or replacement.
