Can my 9 speed be converted to 13?

But nobody wants a 9. I was dealing with Eaton Fuller. I don't think they'll even take a 9 for any credit on a 13, 15, or 18.

Weller and some of the other independent builders might though.

 

No one will take a 9 for core credit unless you want another 9
Last time I was searching for a 13 for rebuilding several places wanted a core….yeah you hear right a core for a freaking core wtf…. I couldn’t even talk them into taking a good working 8ll as a core…. I eventually found one at my buddies yard but had to be patient. I was only looking for one to have on the shelf so it wasn’t a big deal and it payed off.
Oh and if you’re going to rebuild your own you usually come out money ahead to buy one that works but has syncro problems or maybe one set of worn gears when you get into stuff that has a catastrophic failure usually the parts bill gets ugly fast….even if only one set of gears broke, the rest ate the leftover