valve stem size?

[gr8fulabe]

Hey All,
What size valve stem goes into an OEM 40 series rim? I bought some TR415's that I thought would fit (new OEM 40 series rim) as quick research said it was the small stem of the two common sizes. But I can't get the darn thing in at all. Is that the right size, and I'm doing something wrong, or does it take some old school size?
Thanks!

 

[gr8fulabe]

Tr414 - rim hole diameter of 0.453 inches (11.5mm)

believe the above is correct, for any future searches. Lots of stems fit this size. They differ in the stem length. The 414’s seem like a good mix of not to short & not super long either.