Good advice, I will do that, the salt water does a job on those thermostats

change the impeller....even if its good, you need to remove those bolts every year or 2 before they seize.
I know its painful to throw away a perfectly good impeller but it has to be done.
When you get a $25 oil change at 5k miles you throw away perfectly good oil....


just change the T stats while its apart...what maybe $50 a pair, why waste time boiling them... and they'll have new gaskets.

I'd also back flush the engine through the t stats for good measure.
I do my water pump ever other year at least.