SE Quick Intall Tapered pushrods; adjusted for the fourth time and one of the adjustor nuts cracked and another split in half while tightening. This might explain why two pushrods have loosened up since installing this hardware; perhaps the nuts were defective from the factory. I didn't pay attention to the country of origin, so I don't know if they were made in the US or not. The metal appears to be a very grainy, low grade aluminim; looks like potmetal. Has anyone else used these pushrods and had any problems? Question is does anyone have any suggestions for substitutions before I resign myself to the purchase of a new set of pushrods just to get new nuts?