Thanks for the info Ezzett. I read that 1.4Gb is the max GS can support safely. I luckily bloated my textures / models / code so I knew I could go back later to shrink / optimize them.

My levels are pretty massive, so I may shrink them down. I luckily built a world editor that can add models / properties, doors, lighting systems, etc. so this should be fairly quickly.