I have a HSV GTO coupe. V2. Manual. I have recently spent 13k on the engine. (lots of labour done by myself). Im pushing 350kw at the wheels....

Before I did any engine work I was 320 at the wheels. With a raptor supercharger. The raptor blower kits are about 6500. and are a bolt on kit.

Depending how far you want to go..... I had to remove the blower as we built the engine way too big for it. But have my eye on another bigger blower! Just got to sell my VN SS to fun it haha.

Best place to start. Is a exhaust. cold air and a tune. Maybe a cam.

One piece of advice. Decide what way you want to go. otherwise you will redo things over and over again as things get too small that you have already replaced. eg exhaust. Also keep in mind the more power your pushing the more things you need to upgrade. BRAKES!!! clutch, diff etc etc. =)