Throwing PS/Water Pump belt on 340
Check out Hoffman's - Classic probably gets them from them.
http://www.hoffmanswinnerscircle.com/cat16.htm
Also, if a belt is thrown, and it has been stretched/tweaked severely, it'll never run true again. I've seen it. You
may have to throw it away and get a new one. But start with a proper set of brackets.