[Keith Smith]

I was wondering if the P89, P90 and P91 were built on the same frame? I have a P89 and was wondering if I could get a parts kit (everything except frame) for the P91 and convert mine to 40 S&W. Does anyone know if these three pieces are interchangeable?

 

[Keith Smith]

Looking at the mags on GunBroker, I can rule out p90 not being compatible due to the width of the magazine.

 

[COFFEE POT]

They were made from the same casting tool, but with different inserts. They aren't interchangeable.