'94 Full Size Blazer. Replaced the thermostat gasket and upper radiator hose and it's leaking some antifreeze either from the hose at the water inlet or at the inlet and the piece it bolts to. The part store gave me a rubber gasket and it looks like there may have been a fiber gasket on there. Anyone know for sure which gasket is the correct one, or both?

 

Either should work, but there are some cases where, if a fiber gasket is used, the t-stat housing will pit, causing a leak when using the rubber gasket on the t-stat itself. I'd go back to the fiber gasket with some RTV for added assurance.

 

Agreed. Also can throw 2 hose clamps on that hose just to be sure

 

Sounds good, thanks for the information. I'll try both.