Permatex cure time before fire up?

T-stat gasket tach since the parts store had a really thin gasket as opposed to the beefy ones I've gotten from Mr gasket so I wanted some added assurance in addition to the gasket.

Anyways fired it up and had some coolant loss in the exact same spot of the T-stat housing.

I did notice some corrosion pitting in the cast housing when I cleaned it up and I thought the gasket tach would have filled the gap but no... so I'm going to go ahead and get the beefy billet housing from mancini's with a beefier gasket.

I'd first check that your thermstat housing flange is flat, 300 emery on a flat surface like a chunk of glass in a figure 8 pattern. Found lots of them warped even new.