Z11 rear axle assemblies

[Bob Core]

I remember reading in an article or letter about '63 Z-11s in Super Chevy in the 1980s that the rear axle assemblies were unique for them. The author described them as (paraphrasing) "not a normal passenger car unit" but "not a Pontiac rear end either".

Were they actually different than the regular production rear ends? Didn't see anything about in the Z-11 facts section, but I've always been curious about what they were.

Thanks!

[MK IISS]

Bob: Alan Colvin's 1960-64 Chevrolet by the Numbers book has a special section on the Z11s. Page 275-280

"The Z11 differential was a standard passenger car rear axle equipped with a 4.11:1 gear ratio. A positraction carrier was standard. It has been reported in the past that the axles and spider gears were special to the Z11 option, but no proof of this has been found. One owner, Bill Jenkins, has verified this fact."

[Impalaguru]

What Richard posted pretty much covers it. One note is that the Z-11s DID NOT have the second upper control arm from the factory, but shortly after delivery, pretty much all the drivers added them.
Ross