27mm Injector seats/cups/inserts ?

I'm currently in the throws of refurbing a head for my 83 1.8 8v. The problem is I can't seem to find the right size injector inserts anywhere. Mine have an m27 thread on the outside of them. The only ones I can find are all m24. Anyone know what this head might have come off of ? Or where I can get some which are the correct size.
It said in the eBay listing it was a 1.8DX.  

i got mine from vw as they did still have some in stock

hth

Cool, thanks. I'll give them a try. Were yours 27mm and what engine were yours for.
Thanks