Dual hexcore Z600's

[scole of TSBT]

I went digging around on google for images of the guts of both. I have to say, the layout of the Z600 looks less cramped.

Can either of these actually fit the length of a modern GPU? And power connectors?

I think the mobo for each model has two PCIe 2.0 16x speed slots but I'm not sure you you'll never fit two GPUs in them. Not sure what's the max length GPU that will fit. Best I recall, both systems have just one 6 pin PCIe power connector. I have a 750Ti w/6 pin PCIe power in a Z600 and 960 in a T3500 (same basic chassis as T5500) but I power both GPUs with a separate PSU to hopefully make the PSUs last as long as possible.