[Pete]

Sorry to hear of your bad experience with your stripper company.
In order to cool as it should the water jackets need to be bare cast iron as it was
when new. It is a simple chemical fact on what will eat rust and scale out.
I won't go into that here but it is nothing you can buy at the average store.
That is one big reason why the leftist EPA has closed most of the good metal strippers in the country and the ones still in business are getting rich.
A block that is done properly will be bare bright cast iron in the deepest part of the
water jackets when done. Absolutely no evidence of scale or rust.