So everything's all done and dusted, got the car back last night from paramount performance in Toowoomba (great guys to deal with Terry really knows his stuff when it comes to GM V8s) and I'm super super happy with it.
It ended up making 264rwkw/355rwhp (through an auto with a slippy converter) the car sounds completely off it's head I love it so much. Ended up just putting in a new cam, pushrods, valve springs,double row timing chain and getting it tuned, and it made a huge difference (80~ rwkw difference)