>>1774530>>1774558After doing a little bit of reading it looks like it's not going to be a simple drop-in, at least not for a mid drive motor.
I'm going to have to spend a lot of money replacing every part in the drivetrain if I don't want anything to shatter or warp while cranking uphill.
This blogpost I found lays it out well enough I think
https://talesontwowheels.com/2019/09/26/mongoose-chapter-04-motor-musings/