Please help me figure this stuff out

The cam choice will be affected by the gearing. I've ran the 509 withgood results. I'm not as familiar with the other cam.
Dominator carburetor? May be too much for the engine size. The 452 heads will outflow the 516s. There is about 5/8 of a point of compression difference between them, the 516/915 having a closed chamber and more squeeze. The head gasket thickness was also left out. It is critical in determining the compression ratio.
Most of the build looks good. I'd consider subframe connectors, an 850 Holley, a .027 Cometic head gasket to maintain some type of quench and the 452 heads.