alternators for GT6

[Hector Agostini <agostinihp@earthlink.net>]

Hi folks,
        Can someone tell me if the following alternators cna be used
on a 72 GT6 or a 69 Spit:  Alternator from a 7/71 build date MGB, which
has a Lucas with the following markings:
                                                5
                                             1  6  ACR
                                                7
The 5, 6, 7 were in a column between a large one (1) and ACR;
  the second alternator is on a 79 Spit but I could not see any
names or markings.  It appears to be a Lucas.  TIA.
                                Hector