I figure if I can get ~$2k for the turbos (only 4k miles on them), and buy the GT675RS kit for $2750, which comes with the new oil lines (which i'd have to spend $200 on), I'll only be out $550 for going with bigger turbos rather than pulling the engine, putting in the new oil lines, and staying with the 530s. Its just an idea that I'm kicking around, but i've got all the other supporting mods I would need for the larger turbos, so it would be an easy swap over.
It just seems like a waste to pull the engine without doing anything substantial :-)