[SBSerpent]

More thoughts on this topic. Steel backing plate on an aluminum water pump body. The CTE mismatch between dissimilar metals at high temperatures will create stress points where these two metals interact, which is at the gasket and the bolts between backing plate and water pump. Aluminum will expand and contract twice as much as steel for every degree of temperature change outside of room temperature. So I'm wondering whether this phenomenon is causing leaks at the gasket between the backing plate and the water pump.

The leak that I am seeing appears to be between the backing plate and the water pump. The leak didn't manifest until after a few hot cold cycles (i.e. a couple of trips in the Cobra over the course of a week or two).

Gonna remove the w/p and then remove the backing plate, replace the gasket and add gasket sealer on both sides of the gasket. Re-torque the backing plate bolts with LocTite and then re-attach the w/p to the block (using sealer on both sides of the w/p gasket). Hopefully this should solve all leak issues.