I don't "think" so I know so.
The are several differences. Everything from additional standards that don't exist in FAR 25 to different criticalities assigned to specific systems.
If you scan the FAA NPRMs, (Notice of Proposed Rule Making) you will quickly realize that several are dedicated to harmonization with the JARS. So..the FAA is actually incorporating some JAR features in the FARs.
If JAR 25 was an exact copy of FAR 25, what would be the sense in developing it?