Yo Uwe,
Sorry to hear of your problem - my sincerest condolences
Been there, done that:
Threads on distributor gear problems
I ended up with a Crane steel cam using hydraulic roller tappets, and a Crane steel distributor gear carefully located on the shaft to the 4.000" spec. After 9,000+ miles no visible wear when I pull the distributor.
Bottom line: you must use compatible cam & gear materials. Steel/steel or cast/cast.
You can also use a bronze distributor gear but it then becomes a maintenance item with a life of 5,000 miles or so. OK for drag racing but not for street miles.
Carefully assemble the drive gear onto the distributor shaft maintaining the four inch distance
Alas, I fear you may have destroyed the cam, as I did, necessitating its replacement as well
I conclude this after seeing that you found the second distributor gear worn out suddenly as well.
I feel your pain: Ford reimbursed nothing (zero zip nada) even though they installed my gear wrong - I'm out the $2800 parts & labor to correct their mistake.
I hope my diagnosis is incorrect!
Let us know,
Tom