Default [Q] Flash with CM 11

Hi,

I just flashed my phone, using CM 11 to KitKat 4.4.4. Everything went smooth. However, I left 1 GB for data partition and the default size for system and cache. After installing a few apps I found that I have no more space, so I'm gonna repeat the procedure increasing the space for these partitions. My question is how big these partitions (data, cache and system) are in the stock ROM (in my case JellyBean 4.1.2? If I return to the stock ROM do I have to determine the partitions, or it is automatically?