I read that article, and thought about doing the same on my KD4, melting the
slots in the new impeller, but when I held up the drive piece, the lugs just
about went across the whole diameter of the new impeller.
I ended up making a new drive bushing for the new impeller,
using the single slot.
I have not tried it out yet though. To make it work, the drive key, that’s part of the bushing
is a lot thinner than I would have liked.
Prepare to be boarded!