The Stovebolt Site Forums The Shop Area Driveline SM420, earlier vs later

Ok, I was told that the trans case was the same and I would only need to swap the rear bits. If this is not the case, I suppose I'll leave it at that.

What are the chances that the speedo gears in the newer trans would be for 4.10 gears and would make my current speedo more accurate? Pretty sure it came out of a later 3100...