For what its worth, I think that Stops Leaks probably degrades your overall cooling ability on a car that likely has marginal cooling capacity when equipped with a big motor like yours (and yes, even with an upgraded cooling system). A leak is a leak is a leak. As soon as you get that running right the first thing on your to-do list should be to get that radiator fixed and the system purged of Stops Leaks. You can go online and read some horror stories of the use of Stops Leaks.
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