Thank you for all your input guys but I think I'm going to try and buy an already built engine as when you look at the costs involved it's a no brainier. I was originally wanting to keep my bottom end and just sort the head out, turbo etc etc but now realise with the abuse I want to give it that's not going to work. I want a strong 500bhp so it will last.

Any got a 500bhp engine they want to sell