Will the transmission from a Chevy Celebrity wagon bolt up to Grand Prix with same 3.1 engine?

No, a transmission from a Chevy Celebrity wagon (which used various transmissions depending on the year and options) will almost certainly not bolt directly to a Grand Prix with the same 3.1L engine. While they both might use a 3.1L V6, the transmissions themselves, their bell housings (the part that connects to the engine), and even the engine's mounting points might differ enough to prevent a direct swap.

Even if the transmission type is the same (e.g., both are 700R4 automatics), the specific year and model variations can cause incompatibility issues.

You'd need to verify the specific transmission codes for both vehicles to even begin considering the possibility, and even then, you'd likely need significant modifications or custom parts to make it work. It's a highly unlikely scenario for a successful bolt-on swap.