What would you all class as a good balance between horror and gore?

It sorta depends on the story as well doesn't it? Stories involving the deep ones for instance are rather graphic

It depends on what you're trying to evoke in the reader.

If you want shock or disgust, then go for gore. But even then make it fairly discrete and subtle, or else it will fall into Gorno and just be kinda ridiculous. (This is why Rainbow Factory is generally taken a bit more seriously than Cupcakes, for instance: The former mostly implied the gore, while the latter described it in vivid detail)

However, if you are genuinely going for horror, with an intent to scare your reader, go for horror and keep gore at a minimum. In fact, keep alot of the horror itself to a minimum. Nothing Is Scarier, as the trope says, and Lovecraft knew that well. Personally, I find his story The Statement of Randolph Carter to be one of hist most effective, and the closest to a genuinely scary story (Albeit the twist is now a bit of a cliche among horror). Why? Because we have NO IDEA what it is that Harley Warren encountered in that tomb. The only hint we have is the ominous voice that replies to Randolph, telling him that Warren is dead, and the fact that that Warren had been reading various grimoires and eldritch tomes beforehand, but otherwise we have no idea. Was it a ghoul? Was it an Old One in disguise? Was it a shoggoh that had learnt human speech? We never find out, and that lack of clear knowledge is what makes it so effective.

That's what Lovecraftian Horror is: fear of the unknown, the fact that humanity, for all its scientfic achievements and knowledge, in the grand scheme of the cosmos is still insignificant and ignorant of the true powers that be. And humanity in Lovecaft's stories are so ingrained in this delusion that humanity have reached their ultimate pinnacle of advancement and knowledge, that even the slightest hint that what they may know is al wrong, is enough to drive peple insane.

So yeah, if you wanna go for 'modern horror', go for gore and shock value. But if you want to truly creep your reader out, follow Lovcraft's example: keep everything in the shadows. Imply, hint, be subtle.