(almost) everything is possible on Amiga.
But not everything is sensible.
A3640 does even slower memory operations than 030 card on the A4k (Also A1200 with 030 beat A3640 in things like video playback).
Why did you sell the MK2 in the first place?
I have MK1 (&128MB RAM) and I would never ever downgrade to 040. (060 with SCSI would be the dream come true for my 68k Amiga...)
