No real need for alloy valve covers, except the steel one is easily bent. Start with a flat one, either new or panel beaten flat. Then use as large a washer on the screws as you can get to fit, and don't overtighten.
Use a gasket compound (blue hylomar is good) to stick the gasket to the head and don't use any on the other side. That way, the gasket lasts for ages.
