318 Water Pump Bolt That "Always Wants to Leak" Story

I use rtv, permatex brand, but black rtv is what I use on bolt threads into water, and or thermostat housing gaskets. I never use blue. Copper rtv is what I use on exhaust/header gaskets,ball collectors etc.
If the bolt holes are rusted, that's your problem. You probably know that though.

Now 'Permatack' does not work well with water sealing in my experience. I use permatack for oil sealing.. like pans & covers. Just to put it out there..

"The right stuff" works on most anything.

Probably leaked by your hose clamp on the intake.