I just found an old FTE thread with a response from NumberDummy.
C5AZ-10A313-E .. Alternator Mounting Bracket-Side / Marked C7AE-10239-B / Obsolete
1965/68 Galaxie/LTD 240 I-6 without A/C and smog pump (1966/68).
1965/67 F100/600, C Series Tilt Cabs, N500/600, P350/500 240/300 I-6 / Not used on 1966/67's with smog pump.
1968 F100/600, C Series Tilt Cabs, N500/600, P350/500 240/300 I-6, use with or without smog pump, use without factory A/C (F100/350).
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I cannot find C5AE-10039-C but the basic 10039 number cross references to 10A313 .. It looks the same as the other, so it's probably the same.