It's possible you're thinking of Hitmontop which evolves from Tyrogue with a certain stat condition. Here's how it works:
* Tyrogue evolves into Hitmontop if it has higher Attack than Defense.
* Tyrogue evolves into Hitmonlee if it has higher Attack than Speed.
* Tyrogue evolves into Hitmonchan if it has higher Defense than Attack.
So, you don't need any stones to evolve Hitmonlee in SoulSilver. You just need to catch a Tyrogue and make sure its Attack stat is higher than its Speed stat!