Okay so I just upgraded to 3.31s in a 12 bolt. I had 2.56s in my old 10 bolt.

I have 25" tall tires right now with a th350 3.31s in the rear. I will soon have 295/50s in the back. What speedo gear do I need for the 295/50s?

http://chevelleengineer.home.comcast.net/~chevelleengineer/speedo.htm
http://www.chevelles.com/shop/speedo.html

Well that helps a lot! Thank you :thumbsup: