Make RedPower Rubber trees spawn in clusters instead of in jungles

[Vert3x]

Hello there, I'm here to ask you guys if anyone knows a solution, either through config or through a new mod, to make the Redpower's big rubber trees spawn in clusters in their specific biome just like they used to before Minecraft version 1.2, which implemented the jungles and pretty much made them only spawn singularly in that existing biome.