That's probably the same as the original rear end in my 66 GP, I had 3:08 posi 10 bolt but swapped it for a 12 bolt.
Now I have non-posi, 2:73. :(.
Tempted, so tempted...
PM sent for location.
.................sorry, instant. Can't have my English teacher turning in her grave...............
I believe you have to do some mods to get it to fit under your '64 anyway.
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Prince Edward Island
'64 Parisienne CS "barn find" - last on the road in '86 ... Owner Protection Plan booklet, original paint, original near-mint aqua interior, original aqua GM floor mats, original 283, factory posi, and original rust.