Mark,
I've done this conversion before. Most likely the gear in the carrier is a 8 3/4 2.76 non-Sure Grip and you're wanting to replace it with a 8 3/4 3.55 Sure Grip. The important question is what carrier do you have, a 741 or 742. There may be a slight modification for you to make which I can explain later.
Nick Tiberio
FuryUs63
From: "hmsevans via The 1962 to 1965 Mopar Mail List Clubhouse" <1962to1965mopars@xxxxxxxxxxxxxxxx>
Subject: Source for 83/4 Sure Grip Gears
Starting to rebuild the components for my 62 Plymouth,413,auto
I have the rear end disassembled and cleaned.I have 2.73 std gears .I want to replace with a 3.54 sure grip for the street use only.
I plan to use the stock axles and 14" drums brakes on the rear, but use the drum conversion kit.
What is the most reliable New Gear sure grip set package that I use?
Mark