1) Emphasize the value and the impacts of this project.
It is a high profile project.
2) Then, how to excute the project on time and on budget.
Brief your ideas, framework, focus items, milestones,
3) The risks you vision and possible mitigation plan
Here you might slip in the possible issues, would like clarify.
4) Seek his support as the resource, and secure the delegation authority to excel the project on time and on budget.