The Blizzard SCSI-kit 's manual says you have to set the jumper on the Blizzard acelerator to 70ns IF you use 2 SIMMS ( one on the acelerator, and one on the SCSI-ki).
That's
exactly what the quoted part of the German manual says (apparently, the jumper in question is called RAMSPEED). Plus:
"The Blizzard SCSI-KIT IV requires SIMMS with a speed of 70 ns or faster".
Not exactly helpful ;-)