In Fallout 2. Does the Speech skill add anything if your int is around 1-3? Do you get any additional speech options with a low (stupid) Intelligence and high Speech?

What game are you talking about? Fallout 3 doesn't have any low intelligence options that I know of for instance.

Either way, I don't think there are special low intelligence high speech dialogue options in any of them. Just low intelligence options I think.

I don't think so. At least not in older Fallouts and NV. I don't remember there being anything intelligence related options in FO3.

Sorry. I mean Fallout 2. I added it above.