318 driver - cam change or not?

True, but I think that should be the 1st step it to tune to get the best out of your combo, a good tune can be worth a bunch of hp.

But other than that it’s hard to build 30-50 plus hp over stock under 3000 rpm NA.

CR is another way but you can’t go to high before detention.

I agree, which is why I lean towards the OP doing a cam change. He's already done all the rest.