* Engine Bay Size: While the GTO's engine bay is relatively large, the 502 is considerably wider and taller than the Pontiac 400 or 428 that came stock. You'll almost certainly need to modify or fabricate parts of the engine bay, including firewall, inner fenders, and possibly even the radiator support.
* Transmission: You'll need to address the transmission and its mounting. The 502 likely won't mate directly to the GTO's original transmission. You'll probably need a different transmission, possibly a TH400 automatic or a suitably strong manual, and a custom adapter plate.
* Exhaust: Exhaust routing will be challenging, requiring custom headers and possibly modifications to the frame or floor to clear the large engine.
* Suspension: The extra weight of the 502 might necessitate suspension upgrades to handle the increased load.
* Wiring and Fuel System: You'll need to adapt or replace the wiring harness and fuel system to accommodate the Chevy engine.
In short, while mechanically feasible with significant fabrication and custom work, it's not a straightforward swap. It's a project best suited for experienced mechanics with fabrication skills and access to specialized tools. Expect a considerable investment of time, money, and effort.
