How much Roll Cage do I need?

Hi, I have a 73' Duster that is ready for a New roll cage, I have the bolt-on subframe connectors and plan on welding them in. I was wondering if anyone could tell me ...How many point cage should I use for like a 500 HP car? It will be a street/strip 360, Manual reverse pattern 727 trans. 8 3/4" 4.56 rear Strange axles. I recently purchased a 72 Duster that supposedly ran 12.20 on street tires. I'll be swapping all the goodies into the rust free 73' (after lots o work) I'm thinking 8 point ??? From Autoweld Chassis ...... I need input before I buy,
Thanks for sharing , Eric