Need Help on Magnum 360/380 hp Crate Motor Tech Info

Hey guy's,

I have a tech question about the p5249499 Magnum 360/380 hp crate motor with this roller cam .501/.513 lift with .230/.236 duration @.050 with a 108 lobe ..
Are the heads on this motor plain stock heads? If not what's been done to them?
I'm thinking of buying the heads/cam and installing into a Magnum 5.2 with Holley 750.. 904, Hooker super comp fenderwell headers in a 65 Dart 2 dr sedan weekend driver...with power brake and vacuum assist
What size stall converter and gear ratio would be needed?

Thanks