Slant Six Oil light coming on — need a new pump?

I found a '74 Valiant in similar condition so pulled the engine and had it rebuilt. I neglected to have the gas tank boiled out and when I put fresh fuel in there it loosened all the junk and caused issues with the valves. Bent some pushrods doing it. The machine shop took the head back and cleaned it up for me. They said doing what I did was like putting sugar in the fuel. When it flows to a hot engine it will gum everything up, and it did. Pull your tank and have it flushed or replaced.