Hello Everyone, This is my first post. I'm restoring a 1950 Dominator. I have an AMC type gear box I want to sell. I found a laydown type gear box. The AMC gear box has the numbers /letter's NA 3639. That's all I could find on it. I bought the bike as a basket case. Can anyone tell me anything about this AMC gear box such as the year or what it came off of ? Thanks, Lou

Lou: What you have is a AMC Norton box ie the shell is designed to fit in the standard Norton engine plates. You can tell this from the letter part of the stamping-N for Norton. The "A" indicates that the box has the later type of kickstart return spring mounting. Can't remember when this was introduced.The laydown box is ok but the AMC box is better and parts are easier to find. Hope this helps. Regards, Simon.:D