could someone explain how the autozone core charge 300zx caliper thing works?

 

basically you have to return some old ones to prove that you have the car or that your actually replacing them or something...lots of people trade in there stock 240 brakes..some shops have pics to show them what the brakes should look like, others dont..

 

so i could take in some 26mm calipers and get 30mm calipers, for how evermuch

 

It's a possibility, yes. It all depends on who is working and if they know what they are looking at, or even care for that matter.

 

or you could sell me those 26 mms for the core charges and then we are both happy