There are no issue with the oil system on the GTM kit. I do recall some people voicing concern that draining too low using things like the greddy pan or AAM spacer could result in oil burning in the turbos by not draining fast enough, but that was speculation. Everyone I know with a TT kit runs the lines low into the pan or spacer and have no issues. GTM kit actually drains higher if you drill the upper pan like they suggest.

Yes what esfourteen said about using greddy pan or aam spacer.

Here's the link about one oil issue but no word how they fixed it. I had an oil issue but it turned out to be turbo seal going bad and had it replaced. I'm still trying to find the thread that i read awhile back.

E85 Tuning on GTM Twin Turbo G35 : Injected Performance Blog

Also another i just read another thread about catch can. Is this needed if you're running close to 500hp?

As far as catch cans go, most people agree they aren't really needed for most the builds on this forum. Some people are totally for them, others aren't convinced of the need.

I personally have two Saikou Michi mini OCC. They were like $100 custom built and painted. I have them just for a little piece of mind, small price to pay for some reassurance. Over $15000 has been dumped into te Z, what's another $100.