[Cape Codder]

I see there are aluminum timing gears offered by the vendors.
1. Is / was there ever a brass one offered?
2. Does changing to a metal timing gear make more noise than the fiber gear?
3. If an aluminum gear is used how does it fair to meshing with a steel gear as to wear?
4. Lastly, the instructions provided by the vendor description is to have at least .003" lash but no more than .005". What do I do if I can't get those measurements?

Thanks for any and all opinions.