I am not from US but this country is kinda important to all world so according to your law it does not matter if it is pedophilia or aristocrats joke.
In the US all this stuff falls under vague "obscene" category and you legally can be prosecuted to any kind of distribution or even transfer of that kind of material over any public media where it can be intercepted. (originally law was designed for sending obscene materials by mail.)
This is not really limited to guro or porn in general as this law initially was used to prosecute people for writing murder stories or anything else considered inappropriate at that time and totally normal today.
You will not get in trouble for looking at any website including even pedophilia content, at most you can get in trouble for distributing that kind of content.
You'll get in trouble if the powers that be want you to.
Our laws are vague bullshit.
There's nothing illegal about liking guro. I haven't heard of any country in the world that prohibits (or could possibly prohibit) liking anything per se. Acting upon what you like is a whole different story though. My best bet is that GUROchan is completely safe to browse on private premises, in legal terms, US included (it is hosted there after all.)