Hi I have done this myself.
I bought a R380 V8 bellhousing off Ashcroft trans, then used the Td5 release bearing guide, throwout are etc as its the same as v8 stuff.
then the tdi Input shaft has a 7/8" end of the shaft which locates into the spiggot bush where as a v8's is 3/4", so you need a V8 spiggot bush borring out from 3/4" to 7/8" to fit the shaft, it will end up with about 1mm wall thickness but mine is holding up fine.
use all v8 clutch gear.
I did this to my 300 Tdi 110 to put a v8 in and haven't had any problems even with the thin spiggot bush.
hope this helps Ash