Torana hippie, ypur're a new lad around hete, dont worry about all this silliness, i can assist you!
Few years back, we grafted a LJ XU1 GTR original body onto a Subaru Brumby ute chassis, only because the Brumby chassis had a turbo EJ20 engine from a WRX STI 22B rally car fitted to it.
It was sort of wrong, because the rules for Group G rally cars only allowed us to use the car in rallysprints, motorkhanas and hill climbs.
We did make sure we started with an already current registered car(Torana) as to get the new conversion engineered for rego, we though may have been a touch hard!
Anyway, yes, it will work, we know!
If you are going the other eay, ie a Subaru body onto a Torana chassis, you need to get the one particular model LX Torane, the GT-X this was a one off experimental car GM made, hence the X, it had a full chassis, that was supposed to take their then fantastic new flat six engine, desiigned for very low centre of gravity, the body had a very low wedge shaped nose, a bit like Billy the Steam Shovel, from the Mr Squiggle TV show. It looked very futuristic.
Go for it, ypu wont regret it.
We all will!!!