But I will tell you anyway. Aluminum has a fatigue limit. I’m not sure where that is, but I’m not willing to find out. For a race only engine where parts are maintenance cycled, its the deal.
Just like the stamped steel stock ones, work real well with lower lift cams. Go too high and risk poking a push rod through. I believe that was the idea with the street hemi grind cams, designed to work with stock valve train.