14 bolt....do I have a 3 or 4 series carrier?

[Marc Rexroad]

1979 stock gm 14 bolt with 10.5" 4.10 ratio gears.

How can I tell which carrier I have so i can order the right gear set? Changing to a 3.21 or 3.42

Thanks!

 

[bucket]

The carrier split for the 14ff is as follows:

4.10 and numerically lower, 4.56 and numerically higher.

So standard replacement 3.21/3.73/etc will work on a 4.10 carrier.