I bought 2 solids froma old racer.The lifters were all in order.Ran them for about 6 years total.Never had a problem.At the shops I worked at there was never any guarantee when customers brought in their parts.We simply told them even if new and they didnt work that was tuff luck.No warranty or guarantees.If they didnt like it they could walk.You make $$ on parts not just labor.Im not fixing something that I didnt buy but just installed.Rocky