Will a Chevy 454 engine fit in 1994 s-10 pickup?

No, a Chevy 454 engine will not easily fit in a 1994 S-10 pickup. The 454 is a significantly larger and heavier engine than the S-10 was designed to accommodate. While some people have done it with extensive modifications, it's a major undertaking involving:

* Significant body modifications: You'll likely need to heavily modify or replace the firewall, possibly even the frame, to make room for the engine.

* Custom mounts and brackets: Engine mounts will need to be custom fabricated.

* Drivetrain modifications: The transmission and driveshaft will need to be adapted or replaced to handle the 454's torque. This might involve a different transfer case as well if it's a 4x4.

* Cooling system upgrades: The stock S-10 cooling system would be inadequate for the 454's heat output.

* Exhaust system fabrication: A custom exhaust system will be necessary.

In short, it's a massive project requiring significant fabrication and mechanical skills. It's far beyond a simple engine swap. Unless you're experienced with custom fabrication and have a substantial budget, it's not a practical undertaking.