Understanding tag on differential

[ddub]

I have a rear end assembly I salvaged from a 61 Lark VIII, auto, 27 with 3.07 ratio It has a tag embossed with "45B". What does that tag mean?

Don Wilson
53 Commander Hardtop
64 Champ 1/2 ton
Centralia, WA

[JDP]

twin traction

JDP/Maryland


63 GT R2
63 Avanti R1
63 Daytona convert
63 Lark 2 door
62 Lark 2 door
60 Lark HT-60Hawk
59 3E truck
58 Starlight
52 & 53 Starliner
51 Commander

[GTtim]

45 'B' and 45 'C' have different clutch plates and discs. It's all in the manual, in the rear axle section.

Tim K.
'64 R2 GT Hawk