Just buy a just jap return flow cooler for c34 will be ample for what you need! What size injectors did you get?? Have you up graded your fuel pump yet , a shift kit would be the first stop on the list with your current mods , no need for cams , or a rebuild it's a neo god tune and you will be safe as houses ,you will also want a hard intake pipe but don't spend 300+ dollars on one lol and a z32 or the new afm from Nistune , what state you in mate