Jim’s list of GTE part numbers shows two distributor models as correct for the GTE:
Casting C8AF-12127-AD Part number. C7OZ-12127-D
Cast. C70F-1 2127-F,-G Pn C70F-I 2127-F
WCCC shows this one:
Cast. C8OF-12127-G, Pn. C8OZ-12127-G
Mustang Tek lists the applications for these models as follows( all correct for a 427 Fairlane apparently)
The Mustang tek information appears to be from the Ford Master Parts Catalog. There were no Ford branded vehicles built in 1968 with the 427. The only vehicle with the 427 in 1968 was the Cougar.
What you need to see is the Mercury Master Parts Catalog. It will show the listings for the Cougar W code 427 I am unable to access mine right now.
The distributor I am most familiar with is the F version. I cannot tell you if the G was used.
The only ones I have found on original GT-E’s are C70F12127-F with date codes later than July 1967. Not saying others are not possible, but those are the only ones I can verify. Tough date codes to find.