Hi guys, I own an small auto auction, I sell repossessed vehicles for banks, credit unions and finance co. I see a lot of broken cars (car breaks customer tells the bank come and get it) I see enough LS engines with dropped valves caused by broken springs (beehive), I don't know why this happens, I talked to my local dealer service advisor he tells me it's a large problem, all I know if they had a large retainer  and the spring broke chances are the engine would live, what I see now is piston hits the valve damages the head, piston and cylinder (engine done) , however I see many engines (race and street) with lots of hours on them with no trouble, I bring this up because a lot of people are using them, I my motors I won't, I maybe be loosing a little RPM but parts are a lot of money and work.