1969 Ford Fairlane Engine

We had bought this car for $750 with timing issues. We fixed it, I drove it for 4 months, until the head gasket blew. We took it all apart, put it back together with all new gaskets. Now it's the timing again, we aren't getting fire, the carburetor has caught fire a few times. But are we missing something? My dad has been a mechanic for 25+ years and he said he's seen nothing like it and doesn't know what the problem is. I hope you can help.