* Modifications: A 19-gallon tank would require significant modifications to the fuel system and likely the underbody of the Jeep to fit. This would necessitate professional installation.
* Fuel lines: You'd need longer fuel lines.
* Straps and mounting: Existing straps and mounting points likely won't be sufficient.
* Possible clearance issues: The larger tank might interfere with other components in the Jeep's undercarriage.
In short, while it's *possible* to fit a 19-gallon tank, it's not a simple swap. It requires considerable modification and expertise.