Just need to know if i can be defected for putting a turbo in a vk if so how can i get around this and whats the cost on a conversion these days from auto to manual.
Turbo - Yes its illegal, it needs to be engineered.
Manual conversion - You can pick up conversions for cheap, but Id say atleast 300 would be a good start for parts.
If your car is a 202, the turbo setup will deffinately need to be engineered and mod plated. there are a couple of legal registered ones here in NSW, and from what i have heard it is not that hard. The best way I know of is to use the factory EFI manifold, and use an aftermarket ECU, more chance of getting it passed than a carby setup. The factory computer can be used for very low boost as they run very rich in natural from, just plumb in a rising rate regulator. but any more than say 6 psi you will need to run an aftermarket puta.
V8 will have the same legal problems for turbocharging, but there are a few companys doing kits for the EFI 5l, so just swap your head and cam and look at that option as some may already have EPA compliant kits
I converted mine to manual, using a celica steel case ( on a 202, V8 you would probably better looking for a supra or T5) and dellow bellhousing for about 500. the hardest bits to get done was working out which clutch plate to use with standard pressure plate and finding a yoke to fit to the tail shaft. you will also need to locate a clutch pedal box, for a 6 this will be fairly easy, but if it is an 8 you will have trouble find a pedal box, and expect to pay for it too. keep in your mind the pedals are very different and cannot be intercahnged.