What is this strap/bar on Aussie K-member?

Nice one, great looking car and the motor they should have had i have the same torsion bars to go in mine.... currently has the aircon/rt bars 850 i'll go to the 890s.

that ford axle is basically the same as what it had with slightly longer shafts and the disk brakes.

Camaro and firbird IROCZ and TA 82-92 in many cases used the same in the US, they call it a GM 9Bolt. Theirs has 28 spline axles. its a Borg warner/BTR M78 axle used in Oz by Chrysler, Ford, GM holden and Nissan (australian assembled) stll made until about 5 years ago by Spicer Axle Australia

you will find similar in TVRs and Morgans from the UK. TVRs had the 3.7:1 ratio hard to find

M78, robust well beyond what their diminutive size would suggest.
Superlative matrials and engineering in comparison to many other makes.

made in Australia and South africa you basically have a 7 3/4 :)