I recently won a set of MSD 8.5 spark plug wires on Ebay. In the description, the guy said they were brand new in the box. He supposibly abandoned his project engine. Whatever. So i get them and the wires are dirty on the outside and the plastic guides are already in place. The connectors look clean, but how can i tell for sure if these were, in fact, UNUSED? Now I am hesitant to put them on. Any input would be apprecitated. Thanks....

 

Check if there are any scratches on the metal connectors for the distributors.
You can also take on ohmmeter and verify if the electrical resistance of the wires are within or better then stock wires specs (I don't have my Helm manual with me sorry)

 

Cool. They don't appear to have any scratches or anything like that. I went to install them, but they don't seem like they are willing to attach to the plug tightly. They will just pop on and off with the slightest effort. How can I tighten the fit?

 

unfortunatly they all do this,,,its a big problem with msd