Magnum...not cracked!!!!!

I think its more of an aluminum/plastic chinese radiator issue. Now, that said, hotter or extreme cold climates will stress out a pos radiator much more than a temperate climate so in reality, its probably related to both extreme climate and pos factory rad.

In the end, if you count on them being cracked you wont be disappointed when they are. If you consider the price of a valve jov, valves, springs etc... then EQ's at under a grand are a deal. You also get the bonus of a nice HP increase just by bolting them on.

Pishta, it only matters as much as your engine does...if it drops a valve, seat or fills cylinder with coolant, will it matter? In our shop, we dont even use factory mag heads anymore, they all get EQ's.