Got a set of used Green Stripe injectors to replace my stock (187k) orginal injectors. I am going to have them cleaned and flowed but was wondering how many miles these injectors will last when new and is there anything I should look for on the injectors that would indicate a problem. I don't know much about injectors in general and didn't pay a whole lot for them but don't want to take the time an energy to install them if there might be a potential problem. Here are the numbers off the injectors D1720AA, 5207009, 3582. Any info. is appreciated.