I have a 4000T with one of the Sony MPF920-E floppy drives. The drive is High Density but is only recognised as a 880k drive in the Amiga.
I looked at the floppy cable and found it to be modified on the end connector that hooks to the drive itself. The cable has the standard twist in pins 4,5,6 and also pin 2 goes to pin 34 and pin 34 goes to pin 2. The drive itself only needs a jumper to be changed which can be done very easily by just slightly lifting the back half of the top cover up a little and pulling the jumper block off and locating it across the two pins that are parallel with the back of the drive. I have done this on 7 different MPF920-E's and they have all worked.
The drives are relatively cheap
Look hereI just bought 5 drives for about 20.00 including shipping and did the mods to them in 10 minutes tops.
Hope someone will find this useful.
Here is a link to the jumper setting you will want it to look like Drive Select 0
Jumper Setting
