Hi from Aus! 1966 VC Valiant cruiser

The thing is its a 318, it's not a big power house, it has a mild cam and bumped up mild compression ratio. How would they be able to define if I have increased power at all? From the noise? (not trying to be aggressive or a dick)
At the time I submitted my paperwork to Regency, the motor was standard... Comprende....

The car is a 1966 VC Valiant, so it doesn't really matter what engine mods are done in terms of cam, heads, intake, carby as it's all pre 1969 before the first ADR came out. Get around the 1974 onwards mark, then yes they crack down on engine mods.
That's why alot of guys mod Monaro's and Falcon's. Now with this new left hand drive law, I've heard of Camaro's going through with tubs and big motors, where as before they had to be standard.
I'm not sure anyone is 100% truthful when it comes to providing the facts to Regency. I'm sure there's been plenty of stroker motors go through using a standard engine block.
I have info regarding diff size at work I'll share with you tomorrow, essentially if you fit that diff and put it on the paperwork, they will make you have an inspection. Are you tubbing it as well?
The person you need to speak to at Regency in vehicle standards is Jason B or Dave G, they will set you straight.
Do you have the 360 already? If you wanna avoid the headache, I think you should consider a stroker to 318/392. Stock block with goodies inside and 32ci more than a 360.

Yeah sorry, Im not trying to be a smart arse about it, just trying to work out how to best tackle it.

I have a 318 complete but not running and 360 block sitting here to choose from. Was looking at stroker 360 as more piston options and cheaper. I have the same heads as you and an Eddie RPM air gap manifold, Lunati roller rockers and cam kit ( although might go bigger cam ) sitting here to be used on either block. Will also use Fitech injection.

No, not tubbing it only offset spring hangers being used. Ill call them again tomorrow for a chat but might just list it as a stock 360 and not mention the diff, although with the diff width and rims I'm using, the track only changes less than 10mm.

Id appreciate the info on diff sizes if you don't mind. Thanks again.