I am heading to Carlisle next week and hope to find either an upgrade to my existing 8" rearend or a replacement 9". I currently have 2.79:1 open differential and would like to get something in the 3.73:1 ratio with a True Trac or comparable. So I guess what I'm asking is - how do I identify the parts that I'm looking at as a True Trac versus something else? Is there an way to tell by looking (other than gears missing teeth) that a differential is good or bad? I know how to identify a 9" rearend, but what markings do I look for to ensure it is the right size and will not require any trimming and or fabrication? I did a search, read the sticky on rearends etc, but couldn't find what I was looking for. Thanks for any info provided, maybe we can add it to the sticky as well.