Assuming this is going to be a drag strip car, you would need to O-ring the block, convert to steel main caps, use a light weight forged crankshaft, H-beam rods, a high quality forged piston (e.g., JE, Ross, etc.) with full floating pins, a single plane manifold with a Holley carburetor, solid roller cam, stud girtle. Because a 13:1 compression engine is going to put a lot of stress on an engine, you are going to have to build it appropriately. Like the commercial states, "You can pay me now, or pay me later." Good luck!