OF,.. I have a short stem from a Raptor 350... The outlet nozzle is smaller... it's a very, very loose fit for the fuel line ( had to use smaller one that barely fit the carb nozzle), and I had to file a bit on the tank lip to make it seat... Basically, no good...
Later,.. I swapped to the 660 Raptor petcock, ... perfection...
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PS... if you look closely, you can see a slight curve filed into the tank lip, in the above pic that you posted...