its an E40D trans.he's mistaken.yes it's the same trans as the idi's however with upgrades,a different (6 stud converter) and a solenoid pack.
yes,you could place the e40d from an idi behind a psd,however it wouldn't be wise unless it's been upgraded,but it would work.especially if you have one all working,id run 'er.
all you need to do is run the 6 stud converter and the pds's solenoid pack as long as those are both good.
the solenoid packs are easily changed by just dropping the pans.it's the large block with the electrical sensor sticking up out of the hole with an o-ring.just swap in the pds's in your idi's trans.
first though,be sure to see what the trans is doing (or not doing) to make sure its been properly diagnosed and not just a failed sensor or some other electrical issues.