[Aussie Mike]

Hang on, it's a DRB isn't it? That means a DRB body and chassis. There shouldn't be any need to reverse engineer what you have. It'll be pretty obvious it's a DRB just from looking undeneath.

DRB is the most prolific builder of Cobra kits in Australia. They are all built on a Jig so the DRB Chassis are all pretty much the same with only minor chages over time for that series (before they switched to Jag donor DRB2000 kit).

The big advantage of having them all built on the same jig with the same chassis design means they can supply the torsion and beaming report with the kit. That saves the builder a big engineering expense.

The DRB the chassis comes bonded to the body in the kit from the factory. The torana front and rear ends just bolt in.

Your VP LSD diff with be a live axle from a VP commodore with the mounts welded on to match the torana mounts. It's a common upgrade as the original Torana Banjo diff is a bit weak.

The Torana used a triangle 4 link setup in the back much the same as a HQ with angled top links so eliminating the need for a track locater.

There are plenty of people on here who can share pics of their chassis to compare. Can you snap a few pics of the underside to confirm?

There should also be a DRB chassis number you could reference and get more detail on what you have from DRB.

Cheers