No upgrade kit is available for the Accufast KT2 double tabber to allow it to apply 1.5″ tabs. This is due to the number of parts that would need to be replaced. By the time you are done, it would be cost prohibitive.
The Accufast ET is designed to apply 1″ or 1.5″ tabs and will work inline with the KT2, KT1.5, or even a folder!
At this time the only upgrade kit available for Accufast tabbers is the KT Upgrade.
If you would like to rebuild an existing KT2 here is a list of parts Accufast KT2 Rebuild Kit