Helping out a friend!

Not sure why a 6 would be sitting on a V8 K frame. Even if the car still has a 6 cylinder K frame a set of conversion mounts is only about $160 or so from Schumacher Creative Services. The trans is going to most likely be a 904 but the V8 has a different bolt pattern at the bell housing so a swap will require a different transmission. If the rear axle needs upgraded you can bolt in an axle from another A body without moving the spring perches. You would need the shock mounting plates & U bolts. The drive shaft will have to be shortened if the rear is changed. A V8 swap would probably need a radiator change as well. A lot of people on here seem to be having good luck with relatively cheap aluminum ones sold on eBay.

Dang cosgig, I need to type faster!!! And I forgot to mention the torsion bars. And a 70 Duster is a good looking car.