I think I need to explain that I am kind of scavenging information from as many VW sources as possible, for my Audi 10v 5 cyl, KV Eaton M45 supercharging project - basically, a 5 cyl version of the early Golf CIS, hence, my presence on here! I need to convert to EFI and I would be gratefull for any assistance from your members, to overcome this small hurdle.
I think the best way forward, will be to compare the thread sizes of the CIS Audi brass inserts and see if the are the same thread pitch as the 22mm black inserts
Cheers!