422 dyno fail

I was going to run a Edelbrock 800 cfm but I will run a Holley 850 if needed. It’s going in a 71 duster with 727 trans and 3800 stall with a 4.30 gear. None of that matters to my original post as why the hp and torque numbers are low. I’m open to any suggestions to help from a technical build standpoint