Can a Hemi engine be put into 1991 Dodge truck?

Yes, a Hemi engine can be put into a 1991 Dodge truck, but it's a significant undertaking, not a simple bolt-in swap. It requires extensive modifications and custom fabrication. You'll need to address several key issues:

* Engine Mounts: The Hemi's mounting points won't align with the 1991 Dodge truck's frame. Custom engine mounts will need to be fabricated.

* Transmission: The Hemi's transmission likely won't mate directly to the existing truck transmission. You'll probably need a new transmission, driveshaft, and potentially a transfer case, depending on the 4x4 configuration.

* Wiring Harness: The Hemi's computer and wiring harness are completely different from the 1991 truck's system. Significant rewiring, or the use of a standalone engine management system, will be necessary.

* Exhaust System: A completely new exhaust system will be required.

* Cooling System: The Hemi's cooling system might require modifications or upgrades to handle the increased heat output.

* Fuel System: The fuel system might need upgrading to support the Hemi's demands.

* Body Modifications: Depending on the size of the Hemi engine chosen, you might need to make modifications to the engine bay to accommodate its larger size.

In short, while it's *possible*, it's a complex and expensive project requiring significant mechanical skill and expertise. It's not a job for a novice mechanic. You'll likely need a skilled engine builder and fabricator to complete the swap successfully.