Topic: 1969 Mustang 390 - Alternator Pulley

[QKSLVER]

I am working on wrapping up the restoration of my 1969 Mustang Mach 1 which has a 390, AT, AC, PS, PB.  As we approach the finish line we are double checking everything for authenticity.  So my question is in reference to the alternator pulley.

The MCA says the alternator fan, pulley, lock washer and nut should have a zinc dichromate finish.  The MCA parts finish schedule then shows two different descriptions for zinc plate plus chromate.  One description says it should be an iridescent yellow (light/dark yellow or gold) and the other says it should be a shiny olive drab.  With that being said, what is the proper finish for the alternator pulley?  Which of these alternator pulleys should I use?

[Bob Gaines]

I am working on wrapping up the restoration of my 1969 Mustang Mach 1 which has a 390, AT, AC, PS, PB.  As we approach the finish line we are double checking everything for authenticity.  So my question is in reference to the alternator pulley.

The MCA says the alternator fan, pulley, lock washer and nut should have a zinc dichromate finish.  The MCA parts finish schedule then shows two different descriptions for zinc plate plus chromate.  One description says it should be an iridescent yellow (light/dark yellow or gold) and the other says it should be a shiny olive drab.  With that being said, what is the proper finish for the alternator pulley?  Which of these alternator pulleys should I use?

Zinc dichromate is the iridescent gold like the dead nuts on picture . The other pictures show parts that have darkened by oxidation over time most likely.

[QKSLVER]

Thanks for the reply.  Is there a way to clean up the oxidation to restore the factory pieces to their original appearance?

[Bob Gaines]

Thanks for the reply.  Is there a way to clean up the oxidation to restore the factory pieces to their original appearance?

When you clean up you will take off the finish.The gold chromate sticks to zinc . The part is electroplated zinc silver and dipped into the gold chromate and the chromate bonds to the zinc and leaving the gold iridescent . When you clean it that finish will come off and leave the silver zinc  To restore the finish the dark pulleys need to be striped and plating/coating reapplied to the part.