* Spring Perch Location: The spring perch locations (where the leaf springs attach) might be different between the 1967 GTO and the 1970 442. This is the biggest hurdle. You'd likely need to modify either the rear end housing or the chassis to make them compatible.
* Axle Tube Length: The axle tube length may be slightly different, potentially requiring new axles or modification.
* Brake Components: Brake components (drums, calipers, etc.) will likely need to be swapped to match your 1967 GTO's brake system.
* Shocks: Shock mounting points might also differ, necessitating new shocks or modification.
* Exhaust: The exhaust system will almost certainly need to be altered to accommodate the new rear end.
In short, while it's *possible* to make it fit, it's not a simple swap. It would require significant fabrication and potentially custom parts. You'd be better off searching for a 12-bolt rear end specifically designed for a 1967 GTO, or one from a similar-year GM A-body that's more readily compatible. A professional mechanic specializing in classic muscle cars would be best equipped to assess the feasibility and undertake the modifications.
