Generally the crank then flywheel or flexplate-now there can be what seems to be a spacer OUTBOARD of the flexplate, not behind it. It reinforces wheel there at bolt holes to prevent cracks.

What makes you think something else goes there?

The converter when  all the way back must just clear any studs if present on that one, you then pull the converter forward to engage studs or bolts in holes. Meaning converter can seem awful far back, like too far. If flywheel, converter, trans case all correct you simply pull converter forward and button it up to plate.

I've never seen any sort of part bolted between crank and flywheel/flexplate on any engine I've ever worked on, engineering frowns upon that, it makes the bolts much weaker and prone to break.

 In my 40+ years in the auto & heavy truck field I too had never seen any sort of spacer  ***BUT*** the Ford parts book does list one !!!
 And there are 4 of them available NOS.

Well I'll be dipped, never seen or heard of anything like that, learn something new every day.. Wonder what the purpose of it is?.

Venturing a guess...to space the flexplate out from the crankshaft? J/k!!! O.o

Seriously, probably a difference between European and American transmissions. Specifically, I bet there was no auto offered behind the motor in Europe. Just my 2 cents.

I hadn't either, but I bet a 3.0's internal would bolt right in, and if you wanted to source the parts...so too, would the transmission.

I believe the spacer was to enable the use of an available flex plate when using an automatic behind the 2.8. As previously mentioned, the block was not designed for automatics when it was a V4. However I do have a spacer "In the mail" So I hope I can get this thing together.