I got a nice tandem but the seller couldn't find the stoker stem. No hard feelings, because he gave me an awfully nice deal overall.

Is it crazy to use a threadless stem? I've done so, using a thick shim. I see I need a thicker and taller shim to make it really safe. Should I fork out the big bux to do it by the book? I'd rather be frugal.

I could post this in the tandem section or the mechanics section, but you folks are my friends.