MK IA distributor ID – Z5TF-12127-C – # located on the distributor near FoMoCo logo
MK II distributor ID – C5AF-12127-M
These are both later style distributors; the body of the distributor has a casting # of C5OF-12131-A.
This is the distributor listed in most Ford car parts catalogs.
The early style distributors have an oil port: ID – C4OF-12127-A, casting # B9AF-12131-B