Here's why it's complex:
* Engine bay size: The S10's engine bay is relatively small, so finding a V8 that fits without significant modifications is a challenge. Smaller V8s like the LS series (from GM) are popular choices because they're relatively compact.
* Mounting: You'll need custom motor mounts to securely attach the V8 to the S10's frame.
* Transmission: The S10's original transmission likely won't be strong enough to handle the power of a V8. You'll probably need a stronger transmission and a custom driveshaft.
* Wiring harness: The V8's wiring harness will need to be integrated into the S10's electrical system. This often requires significant rewiring and potentially an aftermarket engine management system.
* Cooling system: A V8 generates considerably more heat than the S10's original engine. You'll likely need a larger radiator and possibly an upgraded cooling fan.
* Exhaust system: A custom exhaust system will be necessary.
* Brakes: Upgraded brakes are highly recommended to handle the increased power.
* Suspension: The added weight of the V8 may necessitate suspension upgrades to maintain handling and stability.
In short, while it's *possible*, it's a major project best tackled by experienced mechanics or serious enthusiasts with fabrication skills. It will require significant time, money, and expertise.