Ok if you have stripped window gears plastic off the worm drive or the metal part you will find that ford did not change the guts of these motor for many years. I too a 77 zepher motor and took the worm drive plastic gear and the metal gear and put them in my 66. they are the exact same parts except for the metal gear is of way higer quality being a solid metal piece instead of a two piece. other wise the plastic gear, the black rubber bushings( which are usually the culprit) and the metal gear are exactly the same. Just letting everyone know you have a cheaper option. Just run to the junk yard and grab any 70's window motor and get the parts you need. Now if everyone who fiqures out these little fixs will post them maybe you can make my restoration easier too in the future. Happy birding.