According to the Jegs website, the 3.91 gears will only work on Darts from 72 to 76. Does that sound right? Mine is a 70, but I'd does have the 8 3/4 rear end...
Ignore JEGS website cause it's wrong. They'll work in any 8-3/4 with a 742 case. If I'm not mistaken Mopar used the 742 case from 63-68. Most likely yours is a 741 case. You can verify that by looking on the drivers side of it. There'll be a 7 or 8 digit casting # on it and the last 3 numbers will either be 741, 742, or 489. Factory A-bodies almost always had a 741 carrier. But like I said in your cam thread, you never know if someone has changed it some time in it's lifetime. After all it's 43 yrs. old
