I bought some used gears on ebay (3.73), they were chipped and messed up apparently, and whine like you wouldn't believe, which I'm sure could be the installation. I am not sure which to blame, but I must get these fixed. Common sense for the most part tells me get new gears and go to a trusted shop. I can get a low mileage set of 3.55's from a Mach for really cheep though. Has anyone else had better luck than me with used gears? Or should I stop being cheap (like I have much of a choice) and get new. I just don't want to plop another $350 down and be in the same spot in 3 months. On the other hand it seems like every Mach 1 owner sells thier stock gears and some people have to be buying them and putting them in. This car didn't used to be my DD and now it is again so conservative gear is not of a concern to me but the noise is!