PerformanceParts Garage

MSD has just notified PerformanceParts.com, an authorized MSD retailer, that counterfeit 6AL boxes are surfacing. These boxes are extremely similar to real 6ALs in appearance, but are very different in terms of quality and performance. In fact, MSD has learned of these because of the fakes being returned to MSD as defects. Here are some tips to identifying counterfeit 6ALs.
First, MSD no longer makes the 6420 6AL, it has been replaced with the 6425. Therefore it is unlikely you will find many legitimate part number 6420 6ALs on the street. The counterfeits are 6420’s.
Second, if you can see the unit before purchasing look for these clues. The serial number on all of the fakes is 682013. Also look at the screws used to mount the rev limiter module. MSD only used Torx screws, the fake has Phillips screws. There are other differences in terms of the width of the fins on top and the wiring harness, but only someone very accustomed to looking at MSD boxes could see the difference.
If you find a seller offering the counterfeit MSD boxes please notify MSD directly or PerformanceParts.com. We will see that the seller is shut down.
The replacement for the 6420 6AL can be found at http://performanceparts.com/part/MSD/6425 . You may look at that image to verify you are getting a new, genuine, MSD 6AL.